Top Off Water

[Oscar]

I have had my auto top off running for about 2 months now. It is working quite well but I am seeing quite a drop in salinity in the tank.

I am attributing this drop to the skimmer water. The skimmer produces ~1 cup every two days while my top off is fresh RO. I am trying to keep salinity in ~35% range but it is now sitting ~33%.

I tried to partially bring the tank salinity back up during my last 10% water change by increasing the replacement water to ~40%. That helped slightly.

I think the other solution is to change my top off water to ~10% solution plus continue my water changes at a higher slainity until I get back into my target range.

How do others with small tanks and agressive skimmers dealing with salinity changes?