What I have set at this point is very simple. I have 2- 30 Gallon drums (coke sells used drums for about $20). One is filled with fresh water and is connected to a float switch in my sump. The other tank has saltwater in it. I use one water lifting pump for the top off and 2 pumps for the water change. The water change pumps turn on and off together throughout the day. The problem is that the 2 pumps must have the same flow rate. I checked them and they are almost the same. I also have a second float switch that turns all the pumps off if something stays on or off. It is not a perfect system but it seems to work.
