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F.A.Q Page

Hydro-Gardens

 Frequently Asked Questions Page

We will try to get more & more questions up as we can. We hope this information will help you. If you have any ideas for questions that you feel really should be here, please contact us at [email protected].

Table of Contents

  1. What is Hydroponics?
  2. Why Should I Prune?
  3. How Much Acid Should I Add To Adjust My pH ?
  4. Why is my tomato fruit so small during the winter?
  5. Why are my plants low in Calcium and Magnesium during winter months?
  6. When are the beneficial insects shipped?
  7. How Do I Select a Formula?
  8. What Is A “Southern Vegetable” Plant?
  9. Are there seeds that are bred to be used for hydroponics or can you use just any variety of tomato seeds?
  10. How much growing media does it take to fill a 5 gallon bag?
  11. Are “Grow-Rocks” REALLY necessary or will just plain old rocks work?
  12. What should be the correct ppm of my fertilizer if I am using RO Water?
  13. Why should 10-8-22 formula not be made into a concentrate?
  14. When will I be picking fruit from tomato seeds planted in Mid August?
  15. When should I begin doing my leaf analysis?
  16. What is the highest safe level of CO2 that is recommended in the tomato greenhouse?
  17. What should the reading on my Truncheon be over the source water?
  18. What is the difference between Pelleted & Precision Lettuce Seeds?
  19. Can I get Cinnamite now?
  20. Why don’t you sell Rockwool?
  21. Do nematodes live over winter in the soil or die off?
  22. Are nematodes effective on ticks or chiggers?
  23. Can I grow peppers or cucumbers with tomato formula 4-18-38?
  24. I am getting low PPM readings. Am I mixing correctly?
  25. How long until I transfer my plants & how much water do they need?
  26. Can I mix all nutrients together as a concentrate?
  27. How can I treat algae in my nutrient tank?
  28. Why do the freight rates on your website show higher than what you charge?

 What is Hydroponics?

Definition of hydroponics

plural noun

[ treated as singular ]

  • the process of growing plants in sand, gravel, or liquid, with added nutrients but without soil.

Definition of soil

noun

[ mass noun ]

  • the upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay, and rock particles:

This method of growing plants is believed to have been used to grow plants in the hanging gardens of Babylon over 2,000 BC.

In modern times, the US army used hydroponics to feed the occupation troops in Japan after World War II. The Japanese used human waste to fertilize their crops and the US troops were getting sick when they ate the local produce. The US army brought in horticulturists who set up growing systems to produce vegetables without being grown in the local Japanese soils.

Although true hydroponics would grow plants without using a growing media, today it is generally accepted that anyone who is mixing nutrients into the water that feeds their plants is using some form of hydroponics. Today, some growers use sterile medias, such as; rockwool, perlite, and vermiculite. Other growers use fairly stable organic medias, such as; coconut fiber, peat moss, and coarse aged sawdust. While other growers use a blend of various medias to arrive at a low cost media that still allow their plants to perform at an optimum rate.

The nutrient requirements of most plants change as they mature. Some minor changes are also helpful during the changing seasons of the year. With hydroponics, the nutrients can be changed as the plants mature. This allows the plants to be grown at their optimum rate and usually increases the potential yield.


 Why Should I Prune?

Dear Sirs, I am doing a project at school about hydroponically grown tomatoes. My topic that I have to look up for my presentation is pruning. I need to know why you would prune your tomato plants, when you should prune them, and how you would prune them, as in ripping of the leaves or cutting them. I would greatly appreciate it if you could send me anything about my topic as soon as possible, or give me some internet sites that i could go to, for finding information on pruning.
Thank You E. Cook

Dear E.,

Tomato plants are usually pruned in three ways, lateral shoots, bottom leaves and fruit clusters. I will attempt to explain each of these parts of the plant and the reason for the need to prune.

Whenever possible, it is better to snap the leaves or fruit off, rather than using pruning shears. Pruning shears can smear the juices from one plant into the wound of the next plant and possibly spread diseases. The only pruning job that will require pruning shears is the removal of the fruit cluster after the all the fruit has been harvested. This procedure may require disinfecting the shears occasionally with rubbing alcohol.

The plant has natural breaking points which will allow the plant to heal quicker and not leave any small remaining plant parts that will later die and allow an entry point for fungus. These breaking points are where a leaf attaches to the main stem of the plant. There is also a knuckle, called an abscission layer located behind each fruit on a cluster. Again, this is a natural break point. The lateral shoots do not have a natural breaking point, so it is recommended that these be removed when they are as small as possible.

Tomato plants would like to become a bush. At each leaf, the plant will attempt to produce a lateral shoot, or sucker. If this lateral shoot is allowed to grow, it will become another stem on the plant. When the plants are grown vertically in a greenhouse, usually they are pruned to only one stem – all lateral shoots are removed. The lateral shoots are usually removed when they are 1″ – 3″ long. Allowing the shoots to get bigger only wastes the energy of the plant and will create a larger wound when the shoot is removed. Maintaining only one stem on each plant allows better management of plant spacing and helps control the amount of light reaching each plant and allows for better ventilation around each plant. It also keeps a better balance with the root system and will usually produce larger fruit than you would get from a plant that is allowed to bush. With better ventilation, controlling insects is also easier.

Pruning of the lower leaves on tomato plants is necessary to provide better ventilation around the base of the plants, which helps to reduce fungus problems. It also allows the grower to see the fruit as they ripen, making them easier to harvest. These older leaves begin to age and are no longer contributing to the photosynthesis of the plant. As the leaves age, they begin to yellow and turn brown. They can actually begin to attract fungus, which can spread to the healthy leaves.

As a tomato plant grows, the plant will usually produce 6 – 10 true leaves before it produces a cluster of flowers. After the first cluster, the plant usually will produce 3 leaves and another cluster of flowers. In a greenhouse, the plant will usually be opening the 7th cluster of flowers before the fruit on the 1st cluster is ready for harvest. At this point, the plant would have a full load of leaves (approximately 18 – 21 leaves) for proper photosynthesis and fruit development. A grower usually attempts to keep this number of leaves on the plant throughout the season. Many growers will harvest fruit from 20 – 30 clusters during a growing season. When pruning bottom leaves, only 2 – 3 leaves should be removed at one time. Removing more leaves may cause excessive moisture loss that can shock the plant. If more leaves need to be removed, it is best to wait 2 or 3 days to allow time for the first wounds to scab over.

Each flower cluster on a plant usually consists of 4 to 8 flowers. A grower usually pollinates these flowers and then examines the small fruits when they are 1/2″ – 1″ in diameter. Four fruit that appear to be developing #1 quality will be allowed to mature on each cluster. Any extra fruit – or fruit that is misshapen will be removed before the plant wastes energy developing the fruit. A tomato plant is only capable of holding about 28 fruit at any given time. If excess fruit are allowed to set on the early clusters, the plant will abort the fruit from later clusters. This can cause peaks and valleys in production that can cause marketing problems.

I hope this answers your questions.

Best regards,

Mike Morton President Hydro-Gardens


 How Much Acid Should I Add To Adjust My pH ?

The amount of acid required to adjust your pH depends upon the amount of bicarbonates in your water that must be neutralized. Every water source is slightly different. You will need to add acid into the tank with our 4-18-38 formula, perhaps 1 cup at a time, to see how much total acid must be added. Mix the acid into the concentrate, then run your watering system and check the pH of the solution going to your plants. Continue to add acid until the pH has been lowered to the desired level.

Please keep track of the amount of acid added. The next time you make the concentrate, you can add the acid into the tank before you add the fertilizer. The acid will help the fertilizer go into solution.

The type of acid you use depends upon availability and the nutritional needs of your plants. Battery acid, available at an auto parts store, is probably the most common acid used. Battery acid is 1/2 strength sulfuric acid. This will add additional sulfur to the plants. Phosphoric acid is probably the most beneficial acid to use. It will add additional phosphorus to the plants, which they usually need. Nitric acid adds additional nitrogen and is probably to most dangerous to handle. Both phosphoric and nitric acids are more difficult to obtain and are usually available in large drums. The only acid you should NOT use is hydrochloric acid, used for cleaning bricks & mortar. This acid will add additional chlorine to your solution.

Best regards,

Mike Morton President Hydro-Gardens


Why is my tomato fruit so small during the winter?

During the winter, it takes approximately 8 – 81/2 weeks (56 – 60 days) for a fruit to grow from pollinated flower to harvest. During the summer, it takes approximately 6 weeks.

In the process of photosynthesis, the energy of light fixes carbon dioxide from the air and water in the plant to produce carbohydrates. During the short, dull days of late fall, winter, and early spring, the low daily levels of radiant energy result in low levels of carbohydrate production. Growers who do not supplement carbon dioxide during the winter can also frustrate carbohydrate production because of low carbon dioxide levels within the greenhouse. If the sun shines on a closed greenhouse filled with large plants, it will take less than 1 hour to lower the carbon dioxide levels within the greenhouse to a point where carbohydrate production is nearly stopped.

The size of a tomato fruit is determined by the number of seeds contained within the fruit and amount of soft tissue (placenta) in which the seeds are embedded. The amount of soft tissue contained within the fruit is determined by the amount of available carbohydrates produced by the plant during the time the fruit is developing.

To help maximize the fruit size during the winter, we suggest you cluster prune to three fruit. This procedure should be done from October 1st until February 1st. You should allow the fruit to develop to 1/2″ to 1″ in diameter. Inspect the fruit to determine if it is #1 quality in shape and has a small blossom scar. If it is not #1 quality, it should be removed. Once three #1 quality fruit have set on a flower cluster, the remaining flowers and/or fruit should be removed from the cluster. During the rest of the year, we suggest you leave four fruit on each cluster.


 Why are my plants low in Calcium and Magnesium during winter months?

During the winter months, we talk to several growers who are having difficulty getting enough calcium and magnesium into their plants. They are supplying plenty of these elements in their fertilizer solutions, but the plants are not able to take them up.

We feel the main problem is high humidity within the greenhouse.   The ideal relative humidity (RH) for tomatoes is 60% – 70%. RH levels above 85% create an ideal environment to raise fungus rather than tomatoes. It is important to realize that the RH within the plant canopy may be much higher than the RH in an aisle way.

The main cause for this problem is that during the winter months, the greenhouses are closed for the majority of the day. The plants are transpiring moisture and the humidity within the greenhouse is much higher than during times of the year when the ventilation fans operate more frequently. As the humidity rises, the plants can’t transpire moisture from their leaves as easily. With less transpiration, there is less water (and fertilizer) pulled up through the roots. As a result, the growing parts of the plant begin to show nutrient deficiencies. Blossom End Rot is a potential result from a calcium deficiency. Interveinal Chlorosis of the lower veins is a potential magnesium deficiency.

As a “Quick Fix” to the problem, the tops of the plants can be foliar sprayed with a solution mixed at the rate of 1/2 tablespoon Calcium Nitrate and 1/2 tablespoon Magnesium Sulfate per gallon of water. This solution should be lightly sprayed on the top 2 feet of each plant. Spray at the rate of 3 gallons per 1,000 tomato plants. Spray during the early morning or late afternoon. Do not spray during the heat of the day.

A “Long Term” correction must be made to the humidity levels within the greenhouse. Some growers install a small exhaust fan capable of exhausting a few hundred cubic feet of air per minute, in the upper level of one end of the greenhouse.  Warm air, near the top of the greenhouse, holds the most moisture.   Removing air from this part of the greenhouse also removes the most moisture per cubic foot of air. Depending upon the size of the greenhouse, this fan may run at any time the large exhaust fans are not operating. Smaller greenhouses may need to put a timer on the fan to allow it to operate intermittently.

Also, moving more air around the base of the plants and up through the leaf canopy will help to break up the “micro environment” within the leaf canopy and around the leaf surfaces. As the air moves away from the leaf surface, the transpired moisture is carried away. This air movement also helps to control fungus problems within the leaf canopy.


 When are the beneficial insects shipped?

All of the beneficial insects that are shipped from Hydro-Gardens, ship on Tuesdays with the exception of nematodes.  You need to have your order in by noon mountain time on Thursday to have the bugs shipped the following Tuesday.  All of our beneficial insects ship via air service (except in Colorado).  If you order over $150.00 worth of live insects shipping on the same day, we will ship them next day and only charge you second day rates.


 How Do I Select A Formula?

   I am growing several vegetables in several Hydroponics systems as a hobby. I was wondering what formulas you recommend or would you recommend mixing my own with your Fertilizer Compounds for each of the following vegetable plants:

1.) Green Beans 2.) Cantaloupe 3.) Peas 4.)Watermelon 5.)Sweet Corn 6.)Egg Plant 7.)Okra 8.)Spinach 9.)Broccoli 10.)Cauliflower

Thanks  Todd B.

Dear Todd,

Plants are usually divided into 3 groups. Cool, warm and hot weather plants. Asking yourself when they are grown and what is the climate they prefer, will help you to decide how to group the plants.

I would probably put the following in the ‘hot weather’ group: Cantaloupe, watermelon, sweet corn, and okra.

In the ‘warm weather’ group, I would put: green beans, peas, broccoli and cauliflower.

I would probably put spinach in the cool weather group.

There are some varieties in each of these groups that would probably do fine if they were shifted to the next warmer or cooler group. My expertise is more with tomatoes, cucumbers, peppers and lettuce. None of these items show on your list.

The Southern Vegetable formula 7-14-36 would probably work fine. If you decide to split this into the various weather groups; 8-16-36 Cucumber formula for the ‘hot weather’, 4-18-38 Tomato formula for the ‘warm weather’, and 8-15-36 Lettuce formula for the ‘cool weather’.

Best regards,

Mike Morton President Hydro-Gardens


 What Is A “Southern Vegetable” Plant?

   What vegetable plants are considered “southern vegetables”? Just curious as to which plants I can grow successfully with this formula.

Thanks in advance for any info

Todd B.

Dear Todd,

This formula is used by growers in warm climates to grow tomatoes, cucumbers and peppers. Because of warmer growing conditions, the metabolism rate of the plants is higher and they usually need higher amounts of nitrogen. This formula is usually only recommended for summer growing. If you plan to use the same fertilizer on a ‘year around’ basis, I would recommend that you consider the 4-18-38 formula. Additional nitrogen can be added for summer conditions by increasing the amount of Calcium and Potassium nitrate.

Best regards,

Mike Morton President Hydro-Gardens


 Are there seeds that are bred to be used for hydroponics or can you use just any variety of tomato seeds?

   I’m new to hydroponics and am wondering if it matters which seeds you choose to use when growing hydroponically? Are the tomato seeds that you offer aimed at greenhouse and commercial growers? I will be using my hydroponic system indoors. Can I just use seeds I already have left over from my outdoor gardening season? Are there seeds that are bred to be used for hydroponics or can you use just any variety of tomato seeds?

Thank you, 

Cheryl M.

Dear Cheryl,

All of the seeds that we offer have been specially bred for greenhouse growing. They offer more disease resistance than garden variety seeds. They also have been bred for the gourmet market. Under controlled conditions, these varieties should have more uniform size, excellent appearance and flavor.

Plant breeding can take 20 years or more to get a variety to market. Usually, the variety is only on the market for a few years before a newer variety is released. The cost of all of the breeding must be recovered by the seed companies in only a few years. This is why the cost of our seeds are much higher than garden variety seeds.

Garden variety seeds can be used in small systems and they should grow OK. However, they may not have the disease resistance or the quality characteristics that you desire. A commercial grower would be placing their crop at risk of disease or poor quality by growing garden variety seeds. The larger the number of plants grown in an enclosed environment increases the odds of introducing a disease or fungus that could rapidly spread throughout their crop.

Sincerely,

Mike Morton President Hydro-Gardens


 How much growing media does it take to fill a 5 gallon bag?

    I am new at hydroponics and I am interested in your small greenhouse system, that uses the 5 gallon bags. I myself just built a 10x 20 foot greenhouse and would like to use your system. I just have one question what type of media would you recommend for tomatoes and cukes, and how much does it take to fill a 5 gallon bag?  Please let me know so  I can calculate prices

Thanx Art

Dear Art,

Each five gallon bag holds approximately 2/3 cubic foot of media. The choice of media is up to you. Find a media that is readily available and relatively inexpensive. Many hobbyists use a 50/50 mix of horticultural grade perlite and vermiculite. Others use commercially available peat based medias, such as; Pro-mix, Sunshine Mix or Fafard Mix.

A good media should be disease, insect and weed free. It should be able to drain well. It should be relatively free of any fertilizer that may interfere with the feed you will be supplying. Some commercial growers also use aged, coarse sawdust, coconut fiber, rice hulls, sugar cane waste, sand, etc. If you wish to experiment with different medias, you may find that each have their own quirks, but usually some minor adjustments allow the growers to produce good crops in nearly every media.

Best regards,

Mike Morton President Hydro-Gardens


Are “Grow-Rocks” REALLY necessary or will just plain old rocks work?

   I am VERY new to the hydroponics world and i have a question maybe you can help me with. i have set up an 11 plant ebb & flow system using PVC pipes, a storage bin, and some 2L bottles. i plan to use small pea gravel for my growing medium, i have seen “Grow-Rocks” advertised on websites but are they REALLY necessary or will just plain old rocks work? any help you can give would be much appreciated.
~ Ryan

Dear Ryan,

One of the oldest medias used by hydroponic growers was “pea gravel”. This is usually washed river rock about 1/4 – 3/8″ in diameter. It should work fine – but will be heavier weight. You want to avoid crushed rock. The crushing process exposes new stone surfaces that may release minerals into your solution. I suspect that the “Grow Rocks” are a form of volcanic pumice. This would be a lighter weight than “pea gravel”, but would be more expensive. Another media that may work is perlite. This is a volcanic sand that has been heated until it “pops” like popcorn.

Best regards,

Mike Morton President Hydro-Gardens


What should be the correct ppm of my fertilizer if I am using RO Water?

   Hi I recently bought some of your 10-8-22 mixture. I mix about 10 gallons into my nutrient tank. I check with my TDS meter and it is nowhere near the right amount. I mix 1 tsp per gallon with 1/4 tsp epsom salts. Using this amount, what should be the ppm? What I am asking is if you mix 1 tsp of 10-8-22 with 1/4 tsp of epsom salts into 1 gallon what should be the correct ppm? I am getting below recommended level. I’m using reverse osmosis water because my city water is pretty hard. Can you please give me advice as to what can be wrong? Currently I’m using about double the recommended nutrients just to get about 1000 ppm. I’m afraid I’ll kill my plants soon. Thanks for any help.

Keith

Dear Keith,

It is kind of a “rule of thumb” that 1 pound of fertilizer dissolved into 100 gallons of water should raise the conductivity by 1200 PPM. 100 teaspoons of our fertilizer is roughly equivalent to 1 pound. Therefore, if you are adding 1.25 teaspoons per gallon, I would expect 1.25 x 1200 = 1500 PPM.

Sometimes, reverse osmosis water can cause funny readings from a conductivity meter. Most commercial growers who use RO water, usually mix some raw water back into the mix. Hard water usually contains higher levels of calcium and Bicarbs. The plants usually prefer this to RO water. With hard water, the pH is usually higher and you have to add some acid to lower the pH into the proper range.

I would probably advise you to follow our instructions and not trust your meter. If the plants look like they need more feed, then consider increasing the feed in 10% increments. You will need to wait at least one week after making a change to see the response in the plants. Normally, even with plants under an extreme fruit load, you shouldn’t need to increase feed levels more than 20% – 25% above recommended levels.

Hope this helps,

Mike Morton President Hydro-Gardens


 Why should 10-8-22 formula not be made into a concentrate?

   I notice in your catalog that the 10-8-22 formula should not be made into a concentrate.  Can you explain why?

Thanks,
Matt

Dear Matt,

The reason 10-8-22 can’t be mixed as a concentrate is because it contains Calcium, Phosphorus and Magnesium sulfate. These elements will not react very much at a “working strength” dilution. However, if they are combined in a “concentrate”, a precipitate of either Calcium phosphate (one of the ingredients in cement) or Calcium sulfate (which is the beginning of limestone) will form. When this occurs it removes some of each element from the solution. Once the insoluble precipitate has formed, no amount of mixing will return the elements to a soluble form that will be available to the plants. A layer of sediment will form on the bottom of the nutrient tank. If this occurs, mixing will only contribute to sludge in the water lines and emitters.

Hope this answers your question.

Mike Morton President Hydro-Gardens


 When will I be picking fruit from tomato seeds planted in Mid August?

I planted Match seeds Aug. 15. I am on the the fourth cluster. Please inform me as to when I can expect fruit ripening in terms of days, i.e. Dec. 1st. ? This is my first year as a grower and I have no experience as to when I can expect fruit ripening,

Thanks,
James

Dear Jim,

The length of time required for a fruit to ripen varies with day length and average greenhouse temperature. It is usually measured from the time the flower is first pollinated. During the summer, it takes about 42 days (6 weeks). During spring and fall, it takes about 49 days (7 weeks). During the winter months, it takes about 56 – 60 days. As a general rule, a tomato plant will be opening the 7th cluster of flowers when the first fruit begins to ripen. This ripening time assumes you are maintaining proper temperatures of 65 degrees F at night and 80 degrees during the day.

Hope this answers your question.

Mike Morton President Hydro-Gardens


 When should I begin doing leaf analysis?

Hi Mike,

Please clarify for me when I should begin doing leaf analysis.   Also, your opinion on whether you should leave a “nub” when removing bottom branches or clip off as close to the stem as possible.   I always clipped as close as possible but have read something different lately about a grower that left a nub and snapped it off on the next pruning.  Maybe I have been doing it wrong all along or maybe I just read too much?

I hope you all had a great holiday and have a Happy New Year!

Darlene

Dear Darlene,

Unless you are having a problem with the young plants, I usually don’t think you need a tissue analysis until the third cluster of flowers begins to open.

I do NOT recommend that you leave a “nub” of any size when you remove leaves. There is a natural abscission layer on the stem where the leaf attaches. If you “snap” the leaf off at this abscission layer, the wound will scab over quickly. If you leave a “nub” without any leaf surface for photosynthesis, the “nub” will turn yellow and die. This is a great place for botrytis to get started on your stem. It is more sanitary to “snap” off a leaf and not introduce anything into the wound. If you “cut” the leaf, you are smearing the juices of previous pruning sites into the “cut”. This is a great way to introduce and/or spread disease in you crop.

It is always best to prune leaves when the plants are cool, usually early in the morning. The leaves are more “crisp” and will “snap” easier. Pruning in the morning also allows most of the day for the wound to “scab” over. Pruning late in the day can leave “free moisture” at the wound site all nite. Again, this can lead to more fungus problems.

Hope this answers your question.

Mike Morton President Hydro-Gardens


The highest safe level of CO2 that is recommended in the tomato greenhouse?

  Hi Mike,

I have a question for you guys.
What is the highest safe level of CO2 that is recommended in the tomato greenhouse?

Thanks, Kent

Dear Kent,

You ask a very broad question, so I will attempt to break it into various parts:
1 x 360 PPM CO2 = normal atmospheric levels
2 x 360 PPM CO2 = plant performance improves, bumblebees continue to work well
3 x 360 PPM CO2 = plant performance improves, bumblebees start going dormant
5 x 360 PPM CO2 = plant performance peaks, some people begin getting headaches
10 x 360 PPM CO2 = may be toxic to humans

In a greenhouse, levels could be increased to 700 – 1000ppm without any adverse affects.

I hope this helps.

Best regards,

Mike Morton President Hydro-Gardens


 What should the reading on my Truncheon be over the source water?

  Hi Mike,

I am needing to be told again what the reading should be on my truncheon over the source water reading?

Thanks, Kent

Dear Kent,

Regarding the readings on your Truncheon, a “rule of thumb” is 1 pound of fertilizer dissolved into 100 gallons of water will raise the conductivity 1200 PPM. If the total amount of fertilizer you are adding per 100 gallons is 1.25 pounds then the conductivity would rise 1500 PPM.

Hope this helps.

Best regards,

Mike Morton President Hydro-Gardens


 What is the difference between Pelleted & Precision Lettuce Seeds?

  Hi Mike,

I’m trying to order lettuce seeds and was wondering what is the difference between Pelleted and Precision seeds?
Thanks,
J Caslow

Dear J,

The precision seeds are raw seeds that have been modified to a higher quality seed. The pelleted seeds are precision seeds that are coated with something like a clay powder to look more like a beebe. The idea is that they are easier to work with than the raw or precision seeds that are very tiny.

Hope this helps.

Best regards,

Greg Morton Webmaster Hydro-Gardens


Can I get Cinnamite now?

  Hi,

You show Cinnamite for sale on your website but when I try to put in a quantity to purchase it states it’s not available. Do you have any Cinnamite available to sell?

Thanks,

  1. Albert

Dear T,

The medium length story is – The Company that had the license to sell this product nation wide decided to not sell it anymore. The rights went back to the company that originally created this product. They only have a license to sell in California. So as of today, it can only be bought and sold in California. I will be removing it from our website today to end the confusion of this product.

I hope this answers your question.

Greg Morton Webmaster Hydro-Gardens


 Why don’t you sell Rockwool?

I was wondering why you don’t sell Rockwool?

  1. Senders

Dear C,

The basic issues with Rockwool are 1) it isn’t biodegradable & 2) it ships inflated. If you really want to get technical, Rockwool after it has been used in plant production should be considered toxic waste. Since it won’t degrade and has nutrient build up, it could affect the ground water table at the dumpsite. Some waste management companies won’t take it or will try to charge a fortune to dispose of it.
The 2nd issue is since it can’t be compressed for shipping, you will have to pay much higher shipping rates. For example, our EZ Gro bags ship by truck under class 50. Inflated Rockwool bags might ship at a class 200. This means they are charging you much more per pound for that shipment.
There is nothing wrong from a growing standpoint of using Rockwool. Our only issues with it are 1) it isn’t biodegradable & 2) it ships inflated.

I hope this answers your questions

Greg Morton Webmaster Hydro-Gardens


 Do nematodes live over winter in the soil or die off?

    Hi there.  I ordered some of your nematodes earlier this year and was wondering if you could answer a question. I plan on ordering some more this fall and am curious to know whether the nematodes live over winter in the soil or die off. I garden in zone 7a here in NC. The reason I ask is that I am wondering when I should order and apply them this fall. If they over winter in the soil, I would think it would be better to wait until October or so after the weather has cooled down a bit and there is more of a chance for rain since watering the nematodes into my lawn and garden areas would be a laborious task–especially well enough to ensure the nematodes get into the soil zone to do their work. If they die off over the winter, then perhaps a somewhat earlier application time might be more appropriate.

Thanks for your help in this matter.

Miguel V.

Dear Miguel,

The best way to answer this is to tell you that the best time is to apply them when the soil temperatures are below 90 and above 32. As the soil temp goes down, the nematodes will migrate lower into the soil. They can survive for 2 months searching for a host. If they find one and reproduce, the cycle will start over again for the next 2 months and so on. Most pest insects will return to the soil in late summer or early fall to lay their eggs for the next year. If you have the nematodes established already, they will be much more effective in controlling the pest.
So, the simple answer is to apply them in early fall and give them the best opportunity to get established in the soil. If the pest supply is good enough, you will still have nematodes present in the soil when it starts to warm up next year.

I hope this answers your questions

Greg Morton Webmaster Hydro-Gardens


Are nematodes effective on ticks or chiggers?

  I am curious to know if your nematodes will kill Chiggers and Ticks. Also what is their lifespan or lifecycle. Will we be able to maintain them over the Iowa winter or have to buy a new batch in the spring. We have a brand new 2 acre yard on an 80 acre farm in CRP. Lots of ticks and other bothersome bugs.   –  Hudson

They do not work for chiggers. Chiggers spend their life above ground. Nematodes only work on things that spend part or all of their lifecycle in the ground. You can try Botanigard or other spray. You might just try Orkin or someone like that and see what they say.

Guardian/Lawn Patrol are somewhat effective on ticks. They will only get them in the larvae stage. They will not rid your land of ticks but they could reduce the population. I would strongly recommend that you apply them in the fall at least to try to control them while the ticks try to over-winter.

We suggest a minimum of Spring & Fall applications. It wouldn’t hurt to do more but you don’t need to. By spraying again, you will increase the coverage area of 1st generation nematodes. This should make the control happen quicker.

Refer to the FAQ questions Do nematodes live over winter in the soil or die off? to answer your life cycle question.

I hope this helps

Greg Morton Hydro-Gardens


 Can I grow peppers or cucumbers with tomato formula 4-18-38?

I have your tomato formula 4-18-38. Can I grow peppers and cucumbers with that as well?

Thanks E

Dear E,

Yes, you can grow other plants with the Chem-Gro tomato formula 4-18-38. Certain plants like cucumbers or peppers need a little more nitrogen. So, you will need to supplement those plants with extra nitrogen. Here is what we recommend:

Dilute 1 teaspoon (1 tsp) of Calcium Nitrate (CaNO3) in 1 gallon of water. Each plant will get 1 cup of that solution 1 time per week.
This is done in addition to your daily watering with water mixed with the 4-18-38 according to the proper mixing rates for your age of plants. See the mixing instructions page.

I hope this answers your questions.

Greg Morton Webmaster Hydro-Gardens


 I am getting low PPM readings. Am I mixing correctly?

I am using the Chem-Gro hydroponic nutrient solution in my system. The reason I am writing is to figure out why the PPM readings are so low. I would keep adding nutrients at the required ratios with unexpectedly low results. I told myself there was no way with the recommended nutrient  ratios that the PPM readings should be this low.   At first I thought it was due to a faulty PPM meter. Then I thought my scale was inaccurate. After confirming the accuracy of those instruments I decided to do a test to see how each fertilizer affects the PPM.  Below are my results from mixing each fertilizer separately in a 5 gallon bucket. The water temperature was 73 F.

grams per 5 gallons PPM
Source water 20
Lettuce 8-15-36 12 355
Calcium Nitrate 12 680
Epsom Salt 6 750

Thank you for your time. Any suggestions as to why this is happening would be helpful.

D Studer

Dear D,

It is a rule of chemistry that when you add 1 pound of fertilizer to 100 gallons of water, the parts per million will increase by 1200 PPM.  When adding the 3 ingredients together, based on proper mixing instructions, into 100 gallons of water, you are increasing the PPM by 1500.

12g 8-15-36 should increase the PPM by 600.
12g Calcium nitrate should increase the PPM by 600
6g Magnesium Sulfate should increase the PPM by 375

Combined increase is 1575 PPM

Your weights are correct for adjusting the fertilizer ratios down to a 5 gallon mix.

There are some source waters that have an insulating effect on a conductivity meter and will cause them to read low.  I suspect this is the problem with the 8-15-36.  The Calcium nitrate appears to be reading correctly.  I don’t understand what is in the Magnesium Sulfate that is causing it to read so high.

I would use to 12g, 12g, 6g amounts and not trust your conductivity meter.  Watch your plants, they should do just fine on the amounts of fertilizer.

Best regards,

Mike Morton


How long until I transfer my plants & how much water do they need?
– Various questions from several customers.

Germination to transplant times:

Lettuce & Cucumbers – 2 weeks
Tomatoes – 6 – 8 weeks
Peppers – 8 – 10 weeks
Herbs 4 – 8 weeks depending on the variety
Beans are usually direct seeded, but the seeds are presoaked in room temperature water over night
Strawberries are usually bare root runners that have gone through a cold treatment

Water/nutrient solution usage per day for mature plants:

Cucumbers 100 oz – Cucumbers & Lettuce would do OK on the same formula
Tomatoes 50 oz –  Tomatoes & Peppers would do OK on the same formula
Peppers 40 oz
Lettuce 20 oz
Strawberries 15 – 20 oz – Strawberries need less fertilizer than any of the other plants and would need their own nutrient tank, but can be grown in NFT troughs

We offer manuals on how to grow:

9P097 – Cucumbers
9P098 – Tomatoes
9P099 – Lettuce

All of the seeds we sell are bred for greenhouse production.


Can I mix all nutrients together as a concentrate?
– Various questions from several customers.

There is a rule of chemistry that must be followed:
When making fertilizer “concentrates”, never combine calcium with phosphates or sulfates.  If you do, you will form calcium sulfate (Lime stone) or calcium phosphate (one of the ingredients in cement).  This reaction will lock up calcium, phosphorus and sulfur and make these elements unavailable to your plants.  Once these concentrates are diluted to working strength, the amount of reaction is insignificant.
Our fertilizer 4-18-38 is 18% phosphorus.  Magnesium sulfate obviously has sulfur in it. I suspect you are combining all three components while they are still “concentrates”.  If you poured the appropriate amount from each of the three in separately you probably wouldn’t have a problem and more of everything would dissolve.

Best regards,

Mike M


How can I treat algae in my nutrient tank?
– Various questions from several customers.

First thing to do is to minimize the light that gets into your tank. Keep a lid on it as much as you can. Algae can’t grow without the light. To actually treat the algae in your tank, we like to suggest Clorox bleach over hydrogen peroxide. Mix it at a rate of 1 oz Clorox in 100 gallons of water 1 time per week. Another option would be to use 35% food grade @ 3.5oz of 35% hydrogen peroxide in 100 gallons of water storage tank. Or if you can find 50% technical grade use 2.5oz of 50% hydrogen peroxide in 100 gallons of water storage tank. Hydrogen Peroxide info from Dr Mohyuddin Mirza June 1998

Best regards,

Mike M


Why do the freight rates on your website show higher than what you charge?
– Various questions from several customers.

We have been working very hard to make the cart smart enough to handle the broad range of products that we offer. It doesn’t understand how we can put items in a box so it isn’t giving the accurate freight costs. We have added many, many box sizes to teach it but it just doesn’t get it. We use Flat Rate Boxes with USPS and FedEx as well as many custom box sizes to ensure we offer the best/cheapest options for our customers. We have been in business since 1972 and you can’t stay in business that long by taking advantage of customers. A lot of these new companies roll the cost of freight into the price of the product. That may seem great until you order 2 or 3 or more of that item. You have now paid freight 2 or more times. We don’t do it that way, we charge you what it costs to send you the items you ordered. We don’t profit on freight. I would request you give us a chance and let us quote you the order before giving up on us. If you choose the least expensive option in the cart, we should be able to get it to you for less than that in most cases. There are certain product that have a minimum shipping requirement (Bugs 2nd or Next Day Air) and we ask that you honor those when selecting your freight options online to ensure you have authorized enough money to cover the actual cost of the shipping.

Best regards,

Greg M


Greg Morton.
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