As usual the system didn’t work when I set it up. This time the top float was not working right. when down it was on and when up it was pulsing. So I tried to replace it but I had the control system powered when I went to plug it in and it shorted to 24VAC and welded the float in the on position. I ordered another float and a submersible mix pump as one of them was not working as well. This time I checked the float with a meter and connected it with the controller off but it still did not work! However, the new mix pump did.
At this point I am suspecting my control board may not be working right; at lease with that input. Unfortunately, I made my control board about 8 years ago out of a H32 zone controller by reprogramming it and I have since lost the source code! This may be the kick in the pants I was waiting for to design my own industrial or home hydroponic controller.
At a minimum it would need two float inputs to detect tank full and empty, three mix tank pumps 12V, a 12V water feed solenoid valve output, and a 120VAC relay output for a feed pump. It would also need a screen and some buttons so the user could set some configurations like the time the mix pumps should run and the feed timing.
Ideally it should also have a TDS sensor input and water temperature input so it could also control recirculating systems. And it would be great if it had Ethernet/WIFI for a network based advanced interface and a second 120VAC relay output for lighting control. Then the only thing it would be missing is a PH sensor but that is extremely difficult.
Right now I am using a hearty 12V power supply as the pumps and valves take a lot of current and power the controller through a 24VAC transformer. Then use an external timer for the feed pump. A product that runs off of 120V power is difficult to bring to market as UL testing is expensive.