I have been working on designing the Automated Waterchange System for the Fishroom. Here is the Overview:Fishtanks are drilled for overflow.
The Mixing Valve is set to supply 72*F water.
The Fishtanks are fed with drip emitters @2 gal/hr
The Sprinkler Controller is set to open BOTH Supply and Purge valves at the same time which will begin dumping Tempered Water into the Sump Pump.
The Sprinkler Controller is set to close the Purge valve after 2min; this should allow the Mix valve to flow enough water to normalize the Tempered water temperature to 72*F.
Once the Purge Valve closes, the pressure in the Tempered water manifold will increase enough for the emitters to begin dripping and the tanks will start to overflow to the Sump Pump.
The Sprinkler Controller will then close the Supply Valve after 1 hour, supplying 2 gallons per emitter.
FAIL-SAFE: The Valve operate on 24volt AC which is tapped from the same electrical circuit that the Sump Pump uses. If the Sump Pump has no power the valve cannot operate. Hopefully, no flood!