Is the vent hole too small?

The foam always comes out of the lid even when the skimmer is barely full! the lid is of course not a tight fitting one. should i make the vent hole bigger or should i put something heavy on the lid? the vent hole is around a cm in diameter

here's a picture of the foam overflow

 

Put something heavy on it and let us know what happens.

 

Alright will do it when i get home, the foams are supposed to condense and form a thick liquid in the collection box right?

 

Yep.

See what that does. Does air blow pretty crazy out the vent hole?

Also check to see if there isn't something clogging the vent hole.

I have a feeling that if it is not blocked, the hole is too small. I can't see how making the hole bigger would adversely affect the performance. Actually, as it is, the skimmate may be reduced because the bubbles have to go against pressure to get into the cup now.

What brand of skimmer is it, and how long have you used it?

 

it isn't blocked, i have a feeling it's too small too. yeah i think so too, about the pressure thing, how big is your vent hole? it doesn't blow pretty crazy out the vent hole, quite weak actually, most of the air are trying to get out by pushing the lid out.

It's a DIY skimmer, venturi style i think. used it for a month. the pump is good though, eheim 3000.

 

I have no vent hole technically on my recirculating ASD skimmer, but the collection cup does have a 1/2" or so tapped hole that my cup drain tube attaches to, and that goes to a remote container to collect goo.

So, really it is vented quite well.


I used to have a venturi skimmer on my 35g. And that had a vent hole in the top of the cup. If that hole got blocked at all, it would whistle.


How about adding a drain tube to collect extra goo in case you forget to empty the cup? That will vent the skimmer as well.

 

Sorry.. but how do i add a drain tube??

 

Drill , tap, add a fitting, and attach a tube that goes to an ancillary collection cup.

If you look in the top right corner of this pic, you can see the black tube that goes to a glass. Follow it up, and you will see the fitting, and that screws into the collection cup.


I just realized I have no sump pic with the PVC in my build pics of my 200g tank. I can take a pic showing this fitting tomorrow, and get some of my PVC work, with the skimmer and good stuff in my 75g sump.

 

I disagree with these folks (sorry). From the picture, it looks like the skimmate is building up and pushing your lightweight top up. Air doesn't need a big hole to escape from, and skimmate doesn't build up fast enough to demand high air flow. That's why I suggested putting a weight on top (e.g. roll of quarters) first; then, see what happens from there.

That being said, the drain tube mod is really great. You can go for longer periods without emptying anything. It is also a lot less of a pain to empty the remote container.

 

Hi, i have put a weight on top. now most of the skimmate is being pushed back to the collection cup but some of the skimmate still escape from the vent hole, is that normal?