skimming off the top

[joebcarr]

i was wondering how important it is to have an overflow skim off the top before heading to the sump. my idea is to put a bulkhead in the bottom of my HOB filter. thus eliminating the whole syphon. if the power goes out the suction stops and the return stops......flood proof.

the only problem is i think i need to be skimming off the top.....but im not sure.

 

[burban94]

The reason you would want to skim off the top is because that's where the dissolved wastes tend to accumulate in the water. Skimming becomes much more effective when raw water from the top 1/2" or so from the column is drawn into the overflow. Hope that helps.

 

[WeeNe858]

skimming simply takes off crud like stated above.. that also allows the exchange of gases and lighting . which is good