Bill, Bagada and anyone else who's interested: Since we're holding school, we can do it in a lot of different ways. Originally, I learned on Aerogardens; the self contained table top positive hydroponic growing system. A friend bet me $100 I couldn't grow with any thing else. I figured I'd better do it with something costing less than $100 just in case I failed, but I didn't. I took the easy way out with DWC.
Compared to Rubber Maid tubs I think Sterlite tubs are crap but they have a nice little 10 gallon storage tub that I only fill with six gallons. They're only $5 and it's the same tub Stealth Hydro uses. My bubble tubs are DIY knock offs of Stealth Hydro's unit you can see in their video on their website. I don't feel too bad copying theirs because I think theirs is basically a knock off of Aerogarden's idea, just on a larger scale.
I do use a pond pump to top feed the nutes and for circulation. I do use an aquarium air pump and two air stones. The pond pump is especially useful when the plants are just getting started. With my system you're going to need an air pump forever. I tried Wall Mart's air pumps but I found the ones at the Hydro store to be worth the little extra you have to pay. I especially like the one with the two outlets and the adjustable air flow rate.
I had the same experience with The Home Depot's pond pumps. They look heavier with their three wire cord and plug and the ones from the Hydro store cost a little more but they lasted longer. From the pond pump I go up a 1/2" black plastic drip irrigation line double tie wrapped to a barbed adapter that goes into a drip irrigation head with six outlets. Whether you get the one with the adjustable outlets doesn't seem to make much difference. I use the heavier black plastic 1/4" drip irrigation line to go to the six 5" net baskets rather than the clear air line you see in the Stealth Hydro video. I poke them into the baskets just far enough to feed the babies and reach the starter plugs. I also make sure they're covered with Hydroton to prevent mold forming. I also wrap the pump in a short nylon sock that women wear with flat shoes. Those socks cost about $2 a pair at Wal Mart compared to the pump socks at the Hydro store that are $7 to $15 and they both do the same thing. They keep crap out of your pump.
I also use the 1/4 black plastic drip irrigation line to feed air to the two air stones I put in each tub. It doesn't crush or kink as easy as the clear plastic tubing you see in Stealth's video. I also use a one way check valve in the air line to protect the pump. I like the better quality, fat thicker 'cylindrical' air stones from the Hydro store. They cost a little more but put out more air in smaller bubbles and they don't seem to plug up like the cheaper stones that look like sticks.
The tub is capable of accommodating six net pots to start; two rows of three. Harbor Freight Tools has a great hole saw kit that makes neater looking holes. When the plants get bigger and start to over grow the first tub I get two new tubs and put three holes in each lid. I remove the pump and irrigation lines from the first tub and they go into storage. The second tub only needs an air pump and two stones, like the first. I'm sure you could operate on a larger scale but I'm limited to six flowering plants in my state.
I burn a 'tight' 1/4" hole about 1/4" below the lip of the net pot with a hot ice pick and that's where I stick in the drip tube to feed the babies. It works great until their roots reach the nutes below. When their roots reach the nutes I remove the pump and the rising air will circulate the nutes sufficiently.
As far as pH and ppms are concerned, I don't worry about ppms because I change my nutes about every week to ten days. But I do monitor the pH closely. I'm growing the same bag seed I picked out of a wedding present 27 years ago. I've kept the two obviously different strains going but they like a much more acid environment. I readjust to 5.8 every morning and by the next day they're up to 6.3 or 6.4.
My bubble tubs cost about $54 each to build and they work great for me. You can hang any kind of light over them you like but I chose a cooler four tube rack of T-5's. I can hang them close and they cover my garden nicely. I'd appreciate any constructive criticism, comments or suggestions. HSA
