diy venturi/forced air skimmer question

[rryyddeerr]

hello all. i am making my way back into aquariums. very excited. so much has changed in the last ten years since i had a tank. theres alot to catch up on.
i have recently set up a 42 hex with the intention of making it a fowlr tank. i planned to run a substantial wet dry and a skimmer, but have recently learned that folks arent using bio balls as much anymore???
anyway, it also seems that much more value has been placed on protien skimming than when i last paid attention. so im trying to figure out a reasonably priced but effective skimmer.
i have the basic plans for a venturi driven unit, but havent had much luck getting the type of bubbles i want and have been giving much thought to combining the idea of the pump driven/venturi variety with the countercurrent airpump driven variety.
basically, my idea is to, instead of placing my air tubing and stone in the bottom of the column, place it in a tube oriented on the intake of the pump going into the column. so the stone is easily changed and the air is already chopped to bits before it even hits the pump.
can anyone see the potential pitfalls of this arrangement?
thanks so much. i have learned alot from reading your forums and look forward to sharing my project.

 

[scsinet]

First off, the idea of not using wet/dry is mostly applied to reef tanks. I'd still recommend them myself for FO systems, as you are dealing with lots more DOCs from the additional food and messy eaters that traditionally inhabit FO tanks.
Skimming has definitely gotten big, mostly because skimmer technology has gotten very good.
It sounds like you are talking about using an air pump to drive a venturi. I suppose you could do that, but I'd be worried about the venturi "wanting" more air than the pump can provide, which will mean you are taking a step back.
Normally when you don't get the right bubbles with a venturi, it's because the pump you are using to drive it isn't powerful enough. What kind of pump are you using?

 

[rryyddeerr]

the pump ive been working with isnt the pump ill eventually be using. and the venturi ive been playing with is a diy work in progress. you answered my question about the airstone. in imbalanced ratio of water to air was what i suspected would be the only potential problem, although im sure there are more.
next question, and this should be it for the night since this basically leaves me with work and research to do, is:
would orienting the venturi pre-pump-intake be a bad idea?
that way the pump could maybe act a bit on the air coming in from the valve.
thanks again.

 

[scsinet]

That would work great! Lots of skimmer manufacturers do this, using a modified impeller (often called a needle wheel) to shred the air as it's pulled through the pump. Sometimes people modify pumps to use a "mesh wheel" as well.
My Deltec recirculator has a needle wheel on it, and they are pretty nice skimmers so I'd say that's a good testimonial to how well that works.