Downdraft Skimmers with Bio-Balls

[c griseum]

Looking for maintenance advice on the old-skool down draft skimmers where water at high pressure was forced through bio-balls to create microbubbles.
Any experience with these skimmers?
What pumps work best with them, mostly of the submersible type?
What kind of maintenance and schedule needs to be kept up with the BB to keep them from compacting or producing nitrates?

Any tried and true methods please share.

 

[greg 45]

If this is a ETSS skimmer which it sounds like look at there sight and match it up
people still run them

 

[polywise]

I have a ETSS1000 going on 9 years now.. I know down draft skimmers are energy hogs, but I have had great results.. I clean the bio-balls out +- 1/ year

Jim C.