Video: Build Your Own Self-Watering Seed Stand

comments (0) March 8th, 2009

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Every year I start just over a thousand seedlings for my vegetable, flower, and annual gardens. It is one of the highlights of my gardening life, spending those hours gazing at books, magazines, catalogues and playing with my seed packets as the gloomy, winter weather takes hold outside.

These seedlings make life more bearable for those of us battling cold climates. But the process doesn't have to be so hit or miss. I used to grow the way you probably do. I set up a simple shelf with fluorescent bulbs balanced for daylight in the 5000 degree Kelvin color temperature. I set up elaborate watering procedures and, of course, freaked when I would come back from TV shoots and find that some of seedlings were either dead or shocked. I had to do something, anything to create an automatic system that was simple and would fit into my busy lifestyle and was husband proof.

My original inspiration came from looking at my landscape ponds. They run as a closed loop circuit with water running through the plants. Those, in turn, feed on the ammonia and nitrates created by the fish and waste in the pond, cleaning the water and feeding the plants in a balanced system. Then I learned about hydroponic growing, which is again a closed loop flood and drain system, where the gardener needs to add in nutrients to keep the plants fed and growing. So after some more research and creating a couple of prototypes, I've developed a simple, automatic, Aquaponic seed starting system. It is virtually maintenance free.

It is about using fish, and all they produce, to grow seedlings.

So how can you do it? Start with a shelf. I use a modular metal one, a fish tank with bubbling filter, two plastic trays, shop light fluorescent tube lighting, a low flow pump and pex tube plumbing. The system uses the tried and true method of trays underneath grow lights and a fish tank with a flood and drain pumping system. The fish tank is slightly overstocked with fish, those fish brought in from my ponds. (They are goldfish that have been summering in my ponds.)

If you are just starting out, purchase some "feeder" gold fish from your local pet store on the rate of a fish for every gallon of water. I use fifty gallon tanks, meaning that, for this system, 50 small feeder fish should do. (Expect to thrown down about $7 at your local pet store.)

I set the tank up with an inch of gravel along the bottom and a simple old school charcoal and fiber filter for the tank. The filter is important because as the plants are still sprouts they won't be able to handle the waste the fish produce until they establish a root system and ball and the fish will die without it until the plants can use the ammonia and nitrogen from the fish. Installed in the tank is a small pump, with a shut off valve installed with pex tubing connections. Pex tubing is the greatest invention in plumbing and I just love it. Everything connects together via pressure and all the components are completely modular and color coded to fit. It is available at most home supply stores and very affordable. This pump lifts the water up to the highest shelf in the system and floods the seedling tray on the top layer of the shelf first. I purchased my seedling trays at a container store and they are essentially large Tupperware style trays. To set up the trays, I used a drill to put two holes in the side of the tray. One is up high on the tray and the other is at the very bottom. I installed a pex tube connecting fitting into the bottom hole which I reinforced with a bunch of silicone goop. This keeps the seal from failing, and needs to be checked in on regularly. If it starts to leak, simply add more goop after it has dried.

I use peat chips for my seedlings. I embed the seed into the peat, and place the peat into the tray nestled in with some fine gravel for support so they don't fall over. The gravel helps fill the excess space so the water can drain back out the other hole in the tray. The water then, through the power of gravity, flows down to the next tray which it floods and then back down into the fish tank. The plants grow incredibly fast as they get readily accessible nutrients from the fish tank water and the fish grow faster because they live in a ideal water environment.

For the system to work, however, it requires a series of timers. The water cannot circulate continuously because the plants will drown and there won't be enough water in the system for the fish. The seedlings should dry between watering to prevent mold and root rot. You will risk a catastrophic flood as well if one of the seals fails. I place two timers on a power strip to regulate the system. One timer is for the water pump that I set to turn on once a day and run for one hour. I use the other timer to regulate the lights. I adjust it over time but start out running it 16 hours a day. If you get algae growth, you can add a small amount of barley straw or pellets to the tank. To keep the seedlings strong, I run small fans to simulate wind conditions outdoors to help the stems grow strong and tough for when they go outside into my garden beds. I move the fans around weekly so that the stems get used to wind from a variety of directions. With the timers and fans in place, my work is done.

That doesn't mean you can leave your tank alone. Every other day, I like to check all the seals and regulate the valve to make sure that there are no clogs, overflows or failures. I like to keep the fish tank full up to three quarters of the capacity of the tank. Don't forget, whenever mixing water with electricity, caution must be taken. I use a power strip that has a ground fault interrupting fuse in it, which will help prevent a short or electric shock. So try this unique system and enjoy a worry free, all natural, automatic seed starting system. No matter how small you start, before long, you'll be a seedling machine.

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