HELP my Cheato is Disintegrating.

what is your temperature, alk and calcium?

 

I noticed something interesting this weekend during a water change. I poured the new tank water over my cheato to act as a defuser to stop the water from mixing up the sand silt in my tank. I tested the salinity after I mixed the tank and it was high, so I took a few gallons out of the tank and replaced it with fresh (again through my cheato).

I noticed later that night that the top layer of my cheato turned gray. I think the high salinity to no salinity "burned" the cheato. Any chance you did a water change before this happened?

 

Hmmm..... My DT return T's off and some goes to the fuge, so I when I add rodi topoff water back to the pump compartment an unmixed % also goes into the fuge. I bet it's the brief hypo-salinity every couple days that's doing it. I'll shut off the fuge valve when doing topoff's from now on.

 

This was happening to me also.for the life of me I could not figure it out till I noticed when I toped off the cheato would look weird. that must have been because of the hyposalinity in the sump right with the cheato..now i have it set up different and all is well in the land of cheato...

 

Thanks for the input everyone. I think that explains it.