how to fix??

[rainetheiceman]

I bought this home made skimmer off a friend. He could not get it to work properly. When the pump is on it ends up pumping water out the air intake. He was using a hagen aquaclear 301. Before I starting trying to fix this problem I thought I'd check with the experts!!! Well any idea's??? It stands about 27 1/2 inches.

[der_wille_zur_macht]

Can you give a description of how it is supposed to function? Or at least what type of skimmer it is - countercurrent (airstone), venturi, injection, downdraft, etc?

It's kinda hard to tell what's what in that photo.

[Fizz71]

It looks like a counter current design which is why I'm perplexed that you're using an air intake on your powerhead?!

--Fizz

[der_wille_zur_macht]

Originally posted by Fizz71
It looks like a counter current design which is why I'm perplexed that you're using an air intake on your powerhead?!

--Fizz

That's what I'm wondering about - is the air intake on/near the powerhead, the skimmer itself, etc?

[rainetheiceman]

The air intake is on the output of the powerhead.

[rainetheiceman]

What would you recomend for air?

[der_wille_zur_macht]

If you run the powerhead on it's own, does the venturi (air intake) work? Does it shoot out bubbled air?

[rainetheiceman]

Yes it works fine. Only when the tubing is put on the output does it affect the venturi. I thought of trying a air pump on the venturi, any thoughts???

[Fizz71]

I've had issues with getting an air intake on a powerhead to work when it's hooked up to something rather than just blowing straight out, but I'm no expert on power heads.

However...when it comes to countercurrent skimmers, you usually provide air via an air duffuser (usually wood) at the bottom of the chamber. That's what makes it "counter current"..the water is coming from the top and heading down, the air is coming from the bottom heading up. I built a countercurrent skimmer once and I go sick of replacing the air diffuser..which is why I'm currently "between skimmers".

Where did this friend of yours get the design from?

--Fizz

[rainetheiceman]

He got the design off the net. Not exactly sure where but I'll see if I can find out. He sent me a copy(cut/paste) of the doc. that shows/tells you how to build. The only thing he didn't do was put the air tube in the powerhead intake instead of the output.

[der_wille_zur_macht]

Originally posted by rainetheiceman
The only thing he didn't do was put the air tube in the powerhead intake instead of the output.

Well bingo, there ya go. That's a very common and effective modification for getting air into a skimmer when the powerhead's output venturi isn't working right.

[der_wille_zur_macht]

Originally posted by Fizz71

However...when it comes to countercurrent skimmers, you usually provide air via an air duffuser

Fizz, I suppose if he's using a venturi on the powerhead then it's technically a venturi skimmer, not a true countercurrent.

[rainetheiceman]

We tried that option but it didn't work either??? The impeller didn't like it. What about running an air pump??

[der_wille_zur_macht]

Originally posted by rainetheiceman
We tried that option but it didn't work either??? The impeller didn't like it. What about running an air pump??

Running an air pump to the powerhead won't help. You need the sucking venturi action to get the best results.

Have you tried different powerheads? Did you actually convert the current one or just stick an airline into it's intake?

[rainetheiceman]

No that was my next option, the powerhead he had is not very strong and I think that's probably the problem. Didn't spend alot of time on converting as it didn't seem to want to work. Do you recommend any powerheads?

[der_wille_zur_macht]

The 301 is a ~175gph powerhead. You could try a maxi-jet 1200, they push 295 gph. Or, even a mag 3 or mag 5 pump. . .

[Fizz71]

Originally posted by der_wille_zur_macht
Fizz, I suppose if he's using a venturi on the powerhead then it's technically a venturi skimmer, not a true countercurrent.

Technically counter-currunt is a description of the air vs. water direction. I suppose a venturi could be counter current..but I would think two pumps would be needed or something..I don't know...I'd have to think about that.

...and in order for a venutri intake on a power head to work, the water needs to be flowing pretty fast to generate enough negative pressure to suck air in. I tried to build a setup with a powerhead using the venturi input to suck air out of my overflow utubes and I needed a pretty strong powerhead and it wouldn't work unless it was un-impeeded (not connected to a tube that had some distance and turning to cause resistance). You also need non-collapsable tubing (I use silicone tubing most places..that won't work on a venturi input).

--Fizz

[rainetheiceman]

Thanks for the help. I'll let you know how it turns out!!