Automatic waterchange with top off design - please gimme some feedback

[Milad]

the reason im not using dosing pump is because of the chance of the "drain" getting plugged since the pipes are so small.

Also I could remove the "drain" pump (and one float) then just use the return pump if I could find a 3/4" electronic solenoid. I would put a T connector where the return goes back up to the tank.

If the apex controller will let me, ill do a "turn on until float switch is active" or "2min is up" this way i cover my butt twice.

I also might put a emergency drain from the SW mix tank to the drain on the other side just in case the solenoid gets stuck open and the SW mix tank overfill. Im just not sure if I can put a bulk head on a plastic container.

As far as the return siphon, I haven't decided yet but I might not have under water, might just be barely above the water so i wouldnt get to much siphon.