Algae in My Homemade Hydroponic System

by Mark
(North Carolina)

I'm about 3 weeks in on the hydroponic setup you describe as your best homemade system, and I'm starting to see some algae build-up. Is some algae typical, or do I have a problem Houston?

Answer: Mark, algae by itself is not a terrible problem. The algae does compete for nutrients with the roots of your plants, which can slow down plant growth a tiny bit (hardly noticeable). However, algae dies and is decomposed by microscopic fungi. These microscopic fungi, in turn, attract fungus gnats. If fungus gnats successfully infest your roots, they will chew hundreds of tiny holes into your roots. Each of these holes is an open wound, inviting any pathogen that happens to be present in the nutrient solution to come and infect your plants.

Unfortunately, there are ALWAYS other pathogens present in the water. Therefore, the best strategy is to prevent any physical damage to the roots- and therefore prevent any other pathogens from gaining a foothold. This means preventing fungus gnats and minimizing the growth of any algae.

Algae will grow whenever these three things are present: water, nutrients, and light. In order to prevent algae growth, you need to eliminate any spots in your hydroponic system where the nutrient solution becomes exposed to light. Mostly, this means using a light-proof nutrient reservoir *with a lid*. Also, check the spots where nutrient solution enters the system and where the nutrient solution returns to the reservoir.

There are a couple of other things you can do. Keeping the nutrient solution between 65 and 68 degrees will cause the algae to grow more slowly. Also, keeping the nutrient solution well oxygenated helps eliminate pathogens in the solution and encourages healthy root growth. Finally, using small amounts of Hydrogen Peroxide in the reservoir will help eliminate pathogens, kill algae, and keep the nutrient solution oxygenated.

If you decide to use Peroxide, be sure to read my using hydrogen peroxide page. This page goes into much more detail about how to use Hydrogen Peroxide safely and effectively, and why you DO NOT want to use the 3% peroxide in a brown bottle that you normally find at your corner drugstore. I hope this helps you out Mark, and Happy Growing!

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AffordableGarden Design&Setup

(10 week update below)

Find out the cheapest and easiest ways to garden productively in this article.

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 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.

And when I say decrease operating costs, I mean decrease them to almost ZERO, especially if you are producing your own nutrients...

High Efficiency

The ultimate solution to eliminate the cost of your hydroponic nutrients: Imagine a hydroponic system that does not require you to buy any nutrients, does not require you to make your own compost, and does not require you to brew your own nutrient tea. Seriously! No cost and no effort as far as providing nutrients to your plants! Plus, at the end of the gardening cycle you harvest all of your garden vegetables, PLUS YOU HARVEST FISH from the 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.

Produce garnden vegetables AND fish together. Eliminate fertilizer costs!

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!

If you've found this site helpful at all, I would really appreciate it