Koi Forum • DIY Protein Skimmer / Foam Fractionater : Koi Water Quality

I have knocked up a 1.5m, 4″ pipe foam fractionater as described by Manky in the magazine.

It works but obviously it needs very delicate adjustment to get the air flow right so that bubbles form and to get the level and depth just right so that the bubbles push out of the funnel.

The downside is that it takes water from deep in the pond and most of the DOC’s are probably at the surface (I get loads of bubbles and some scum when I turn the bakki on and with it off, I get that oily sheen on the surface indicative of high DOC content (its not oil!)).

I’d like to knock one up that takes a feed from the skimmer (as the oily surface currently goes straight through the skimmer basket and through the UV and pump and is mixed back into the pond) and I have seen protein skimmers that appear to trickle over media – how do these work and are they less susceptible to flow, pressure and level than the ‘air in a column of water’ fractionaters that Manky proposed?

4200 gall,dug in 2000, f/glassed (& weeping),Nexus 200+Eazy,Cetus Sieve,Prem Bakki+12 box bhm+ 2 bags Bacballs,Certikin skimmer / collar weir, Badu Top 10+3x Aquamax Eco 8000+2x Secoh 100lpm+2x Spindrifter+55W UV (+BBF1 b/bead yet to plumb in)