Saturday, October 23, 2010

New Design - OUT with you half-barrels!!

After trying various half-barrel configurations and bell siphons, I decided half-barrels just aren't the way I want to go. The bell siphon alone takes too much space in each barrel, and having 16 bell siphons just didn't appeal to me. Also, the depth in each barrel is obviously not consistent due to the curvature of the barrel. If I were doing a small system, and just had a few barrels to set up, that would be one thing, but since I am setting up a decent-sized system, I'd rather do it right from the start.

I redesigned my layout based on larger grow beds, of about 525 liters each. After getting quotes from fiber glass shops on these one-off beds, and just as I was about to put a deposit in for an order of four, I discovered a local manufacturer of various rubber-based products, including tanks, pools, and water-reservoirs for cattle. It turns out the cattle reservoirs are perfect! The cost of these was about 40% less than the fiber glass equivalent.

Today I finished setting up the system with these new grow beds. I went ahead and planted what we had available - basil, arugula, and peas. I probably should not have done that before testing the water, which turned about to be PH 8 !! This water comes from a natural spring on the property. I figured that was better than tap water, and other than the PH, it probably is.

I went ahead and added crushed egg shells to the system to reduce the PH. I placed them in a make-shift left-over mesh-bag from my greenhouse screens, tying that to a plastic bottle, and floating it in the fish tank.

I have no idea how long it takes for the calcium carbonate to dissolve and bring the PH down, but egg shells are supposed to make for a good PH regulator in AP systems. I'll test it tomorrow and see if it has come down any. When it gets below 7, I will add my Tilapia.

For now, I'm priming the system using "Humonia".

Here some picks of Day 1:

All three bell siphons going. Yes, the water is damn murky. That's due to the gravel, and should settle out in a few days.

This grow bed is a used bath tub. If I could have fount five more of these, I would not have bothered with the water-reservoirs for cattle.

Backup pump system and air pump.


  1. My crushed eggshells, as I soon found out, will never bring the PH down. They are for bringing the PH up! No harm done though, as the calcium in the egg shells only dissolves in low PH. That's why it's a good stabilizer - it goes into solution right when you need it - at low PH, and then brings the PH up.