ekovalsky
06/24/2008, 11:33 AM
I have been tweaking my AP902 skimmer and wanted to clarify the optimum water level for it. This probably will apply to the entire AP series and not just the AP902.
Skimmer is supplied by a gravity feed from a "herbie" drain (i.e. bulkhead with strainer only) in the overflow. Bulkhead is 1-1/2" and I maintain this diameter with PVC pipe to a valve right before the skimmer intake, where it is reduced to 1". It is a ball valve but I plan to replace with a gate. There is a secondary overflow drain fitted with a standpipe. Return pump is a Dart which is adjusted to keep a slow steady stream running through the secondary drain, thus maintaining a constant water level in the overflow and a stable pressure had on the "herbie". This setup has worked really well, providing high gph to the skimmer without any bubbles and an exceptionally stable water level. I previously was using a standpipe on the skimmer bulkhead, and there were always big bubbles entering the skimmer not to mention an less than perfectly stable water level.
So where exactly should the water level be in the skimmer ? Assume both Eheim pumps running with taps closed, i.e. no air, and bubbles have cleared from the skimmer water.
I've read the manual and various threads on RC and still am not exactly clear on this. Manual says something to the effect of "just above the bottom of the bayonet" -- is this the bayonet threads on the skimmer neck itself, or the 3/4" or so tall receiver for the bayonet threads on the skimmer body ?
Easiest way to convey the appropriate water level would reference the junction of the black ABS bayonet threads and clear acrylic neck at the buttom of the removable neck/cup assembly. Should the water level be exactly at this junction, just above it (i.e. so you can see the meniscus through the acrylic at the bottom of the neck), or just below it ? If the latter, how far below it ?
Right now my water level is about 1/2" below this ABS-acrylic junction. I have the ball valve on the skimmer input about 75% open, and the ball valve on the outlet/effluent pipe about 80% open. I don't know the exact gph but it is a lot, at least 600- 800gph, and this is essentially the maximum water flow the Dart can push through the return plumbing against its head pressure. If I open the inlet valve any more, I lose the secondary return flow and water level in the overflow drops resulting in a rather loud waterfall. If I open the outlet valve any more, water level in the skimmer drops too low.
I generally set the airline taps at around 12:30, to have the tiny bubbles break about half way up the collection cup.
Thanks for any suggestions.
PS -- AP902 is technically oversized for my tank, but it is overstocked (40 fish + over 100 corals) and I feed heavily since there are some aposymbiotic soft corals, gorgonians, and sun corals. I get good nog some days, not so good nog other days. I do use the cleaning head which runs for five minutes every four hours. It does a pretty good job of keeping the neck clean and the flushing system has basically eliminated odor. I still wipe the top of the neck down every few days and clean the brushes 1-2x per week -- they get very nasty!
Skimmer is supplied by a gravity feed from a "herbie" drain (i.e. bulkhead with strainer only) in the overflow. Bulkhead is 1-1/2" and I maintain this diameter with PVC pipe to a valve right before the skimmer intake, where it is reduced to 1". It is a ball valve but I plan to replace with a gate. There is a secondary overflow drain fitted with a standpipe. Return pump is a Dart which is adjusted to keep a slow steady stream running through the secondary drain, thus maintaining a constant water level in the overflow and a stable pressure had on the "herbie". This setup has worked really well, providing high gph to the skimmer without any bubbles and an exceptionally stable water level. I previously was using a standpipe on the skimmer bulkhead, and there were always big bubbles entering the skimmer not to mention an less than perfectly stable water level.
So where exactly should the water level be in the skimmer ? Assume both Eheim pumps running with taps closed, i.e. no air, and bubbles have cleared from the skimmer water.
I've read the manual and various threads on RC and still am not exactly clear on this. Manual says something to the effect of "just above the bottom of the bayonet" -- is this the bayonet threads on the skimmer neck itself, or the 3/4" or so tall receiver for the bayonet threads on the skimmer body ?
Easiest way to convey the appropriate water level would reference the junction of the black ABS bayonet threads and clear acrylic neck at the buttom of the removable neck/cup assembly. Should the water level be exactly at this junction, just above it (i.e. so you can see the meniscus through the acrylic at the bottom of the neck), or just below it ? If the latter, how far below it ?
Right now my water level is about 1/2" below this ABS-acrylic junction. I have the ball valve on the skimmer input about 75% open, and the ball valve on the outlet/effluent pipe about 80% open. I don't know the exact gph but it is a lot, at least 600- 800gph, and this is essentially the maximum water flow the Dart can push through the return plumbing against its head pressure. If I open the inlet valve any more, I lose the secondary return flow and water level in the overflow drops resulting in a rather loud waterfall. If I open the outlet valve any more, water level in the skimmer drops too low.
I generally set the airline taps at around 12:30, to have the tiny bubbles break about half way up the collection cup.
Thanks for any suggestions.
PS -- AP902 is technically oversized for my tank, but it is overstocked (40 fish + over 100 corals) and I feed heavily since there are some aposymbiotic soft corals, gorgonians, and sun corals. I get good nog some days, not so good nog other days. I do use the cleaning head which runs for five minutes every four hours. It does a pretty good job of keeping the neck clean and the flushing system has basically eliminated odor. I still wipe the top of the neck down every few days and clean the brushes 1-2x per week -- they get very nasty!