Our 90g tank runs for awhile (days), then starts spitting out air bubbles as the sump water level is below pump intake. Which is normal. And normally caused by evaporation.
System is a drilled tank with sump that drains to a drain section with filter sock, to a center skimmer/refugium section. over a baffle to the sump/return section. Under normal operation the baffle sets the center skimmer level at say 6" then the return section has a level of say 4" or so.
But what has me confused is we turn off the pump and the levels in the skimmer and sump sections rise several inches above the baffle with both sections the same level. Which actually is normal. But when I restart the pump the levels do not return to the previous levels but remain a couple of inches above the baffle.
So today I cleaned up the algae in the display return teeth before restarting the pump. I guess that could provide some blockage. And the sump level was above the baffle.
I think the levels not returning to previous running levels would mean that some blockage was 'cleared' by turning the pump off then back on.
Am I on the right track or is there something else I might check?
TIA
System is a drilled tank with sump that drains to a drain section with filter sock, to a center skimmer/refugium section. over a baffle to the sump/return section. Under normal operation the baffle sets the center skimmer level at say 6" then the return section has a level of say 4" or so.
But what has me confused is we turn off the pump and the levels in the skimmer and sump sections rise several inches above the baffle with both sections the same level. Which actually is normal. But when I restart the pump the levels do not return to the previous levels but remain a couple of inches above the baffle.
So today I cleaned up the algae in the display return teeth before restarting the pump. I guess that could provide some blockage. And the sump level was above the baffle.
I think the levels not returning to previous running levels would mean that some blockage was 'cleared' by turning the pump off then back on.
Am I on the right track or is there something else I might check?
TIA