Hydroponic CO2 and/or pH Controller in the Water?

by Vincent

I have a little hydroponic setup where my pH creeps up very quickly. It changes from 5.8 to about 7 within one day, and I have to add pH down for vegetative growing every day. So, to keep the right pH, I have to adjust this twice a day.

I've heard they sell pH and CO2 controllers for aquarium's, and was wandering if this could help to maintain the correct pH level in the reservoir. Best regards, Vincent.

Answer: Vincent- pH controllers are usually kind of expensive. The ones I have seen have a small reservoir of pH down as well as a monitoring sensor. Whenever the pH creeps up too much, the device delivers a small amount of the pH down to the nutrient reservoir automatically.

More recently, I have had two different visitors mention a device that adds CO2 to the water to control it's acidity (pH). My gut feeling is that it would work, as fish aquarium pH is usually in the same range as a hydroponic system's pH....although I don't have any personal experience with this device, and am not sure how well it works in a hydroponic situation. However, I do have a couple of other ideas that may correct your problem without very much additional expense.

A well designed hydroponic system should contain about 3/4 gallon to 1 gallon of nutrient solution per plant. I use this as a minimum guideline whenever I am putting a homemade hydroponic system together. The volume of nutrient solution acts as a buffer that slows down the speed at which the pH will change. The more solution, the more buffer you have. If you are using less nutrient solution than this, it may be part of your problem (and part of the solution).

Also, different brands of hydroponic nutrients vary considerably as far as what pH they mix up at and how quickly the pH begins to change once mixed. Earth Juice, for example, requires a LOT of pH adjustment. You may be able to correct your problem by changing to a different brand of nutrients. A product line called Canna Bio, for one, mixes up at just the right pH and requires almost no adjustment from day to day! This not only eliminates the need for a controller, but also the need to buy so much pH down.

I hope this helps you out Vincent, and Happy Growing!

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(10 week update below)

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Hi everyone, Jason from Jason's Indoor Guide here. When I got started with hydroponic gardening more than 24 years ago, my first garden used rockwool cubes and B.C. Nutrients....and I remember thinking to myself yeah, sure, there may be a lot of advantages to gardening with hydroponics, for example there are very few pest problems, therefore very little pest control, no weeding, no plowing or tilling the soil, no soil testing or having to add things into the garden soil, no watering the garden....but for someone who just wants to grow their own vegetables and have more control over their food supply and the quality of the food that they eat, the cost of constantly having to buy grow media and hydroponic nutrients makes this an expensive hobby for most people...

Epic Nutrient Change

I suppose when you take into consideration how much money you save NOT having to buy food at the grocery store, it is surely cheaper to grow your own food hydroponically even with the cost of high quality nutrients. Nevertheless, I didn't have a whole lot of money to work with and I needed to make my efforts as affordable and effective as possible....and in the last 24 years I HAVE learned a thing or two!

As you browse through Jason's Indoor Guide, you will notice all of the systems that I use personally are homemade systems. As I got 3 or 4 years of experience under my belt, I quickly adopted a preference to standing water systems and systems that use expanded clay pellets or lava rock, because the media is re-usable and it eliminates a huge operating expense. So once a hydroponic system is built, garden maintenance is minimal- check and adjust the nutrient solution daily, and to change it completely every 2 weeks....and the biggest operating cost is the hydroponic nutrients. (and the electric bill, lol)...

Homemade Cloner

And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient teas....like kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.

Unfortunately, I have been gardening for over 24 years and I have only just recently mastered this difficult skill....and even then, only because I happened to find a very easy to follow, high quality technique and decided to follow the instructions to the letter. I produced more high quality compost in just one week than I was able to use in a whole year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to increase the productivity of your food production efforts, while at the same time decreasing the amount of effort required to grow all of your own food, and decreasing the total cost of operating your food production system.

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This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.

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Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!

The Same System/ 10 Weeks Later!

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