Surface Skimmers

[David Aiken <daiken at iprimus_com.au>]

I've had an Eheim Surface Suction Extracter for years but keep taking it 
out of use because it's difficult to keep it operating effectively as 
the water level changes due to evaporation in an open topped tank, and 
because it also doesn't handle the flow rate of my Eheim 2222 all that 
well. It has a tendency to end up dumping air into the filter which 
interferes with the filter operation, plus it can be noisy.

I bought an AquaClear Surface Skimmer a couple of days ago. it's a 
different design to the Eheim, seems to handle water level changes 
better, and allows adjustment of the amount of surface skimming that 
occurs so you can avoid it gulping air into the filter. Operation is 
also quieter.

It's a bit tricky adjusting the skim rate, and it seems you don't want 
too much surface water skimmed at all if you want it to work without the 
air gulping and noise but it's not difficult once you get the trick of 
it. I'm not certain, however, that it would handle filters with higher 
flow rates than my 2222 which is the smallest of the Eheim professional 
series. It seems to work best for me very close to the end of the 
adjustment range which is one of the reasons adjustment is tricky - 
you're working in a very narrow effective adjustment range with the flow 
rate from my filter. The end result, however, is a pristine water 
surface without the slight filming that has been annoying me, and very 
much improved light penetration into the tank. The water, which was 
always clear, looks even clearer and the whole presentation of the tank 
looks much better. So far it's early days but I'm very impressed with 
the device despite the limited adjustment range with my filter.

Does anyone know of any good surface skimmers that handle high flow 
rates, operate silently, and don't pass air to a cannister filter?

David Aiken