Here in Southeast Louisiana the temps range between 30's and 90'0, I'm on my second pump in three years. I have a flood and drain system which runs continuously. My bell siphons have to be cleaned occasionally. But they are dependable. I want to go to a timed system supplying water through a zone valve serving 8 IBC grow beds. I have a 325 gal fish tank and a 250 gal in ground sump both supporting a total of 125 gold fish. My question is about time devoted to each set of grow beds. Can the no flow periods be as long as a half hour?
I have talked to several people and have been told that 10 minutes on and 50 minutes off will work. So until I hear differently that is what I am going to try to do.
I am putting together a NFT system with flood and drain grow beds. All of my system is going to be indoors in an indoor arboretum. The fish will be in the basement along with the grow beds. The NFT pipes will be upstairs in the arboretum that is served by both natural and artificial lights.
I'm right there with you on the climate. I live in BR and have a small patio system I've been running for a couple of years. My system floods and drains every ten minutes. Mine is much smaller than yours. I have only two grow beds and a 150 gallon tank with thirty bream in it. The plant requirements for AP are the same for any other type of growing system. Look at your plants. Are they wilting in the 95F+ temp between cycles? Controlling the water temp and cycle is crucial in our environment. I put radiant barrier around the fish tank and shade cloth to prevent afternoon sunlight heating it up. I wish I could bury my sump tank to help but my landlord wouldn't like me digging up his patio. I opted for radiant barrier around the sump tank as well. Bream are much tougher than gold fish (and you can eat them). I started with a thirty minute cycle but shortened it when I noticed the plant stress in the middle of the summer. How are your pH levels after a few years and what do you do besides water changes to alleviate it?