Eric Gerber wrote:Hi all,
I am planning my aquaponics setup. I am in Central Texas,
Why are you trying to fight nature? ALL Tilapia is illegal in Texas without a permit. It is a serious pest, and it doesn't like our weather (above ground tanks aren't subject to the geothermal cooling that lakes are, your water temperatures will rise to reach equilibrium as your air temperatures rise. )
Which brings me to my next point. Texas Perch, Bluegill, and Catfish. All of these fish are accustomed to living in the Texas heat and taste delicious. Not only that, but you can go out fishing and catch your tank stock.
If you absolutely insist on Tilapia and you get the permit, you could also geothermally maintain the temperature in your tanks. Dig down below the freeze line (rent a backhoe) and bury several water holding tanks with a volume greater than that of your fish tanks. These will make up your heat sink and cool/heat your water. (The temperature below the freeze line around here is 68 degrees year round) circulate water from this tank to your fish tanks to maintain water temperature. By controlling the flow, you can control the temperature and recreate the environment these fish can thrive in. Another advantage is that you can stock more fish in your above ground tank because the plants have more time to filter it.