Evaporation

[austinsdad]

I use this one.
JBJ A.T.O. - Automatic Top Off System Water Level Controller

Use a 37g tank for FW with sensors in the sump and the FW tank so the pump doesn't go dry.

 

[thincat]

I use this one.
JBJ A.T.O. - Automatic Top Off System Water Level Controller

Use a 37g tank for FW with sensors in the sump and the FW tank so the pump doesn't go dry.

The trouble with JBJ is that if you disconnect the audio sound you void the warranty. Also if one of your level switches go bad it is expensive to replace.

 

[BucJason]

Probably true, but my PH never seems to vary much between water changes, and if it does I have PH buffer just in case.

If you have an R/O water filter then I wouldn't worry about evaporation either, but buying jug after jug of distilled water gets expensive and a hassel. I don't have corals or anything that need high-powered lighting, so heat is not a problem . I have fish only, so small fluctuations in PH is not huge problem either.