Back pressure from inTank skimmer cup?

[Mushroom Boy]

Good morning,

 

I posted this over in the general forum, not realizing there was an inTank forum as well. Anyway, my question is regarding the inTank cup for the Tunze 9002. It seems that when I have the lid firmly attached to the cup, it creates back pressure and doesn't allow any skimmate to form. Is this normal? Any tips or ideas? I've basically been running it with one side left loose to allow air to escape.

 

Love your products btw, very nice craftsmanship!

 

Thanks!

Paul

[inTank]

Hi Paul-

 

We have never herd of this issue before and a hole was never designed in the lid. In your case a small hole in the lid or notch in one of the walls seems that it would fix your situation if you want to keep the lid on all of the way.

[Mushroom Boy]

Thanks for the info. So, with the lid firmly in place, skimmate is produced? My skimmer only seems to function with the lid partially left ajar. I'm going to play with the depth of the skimmer to see if that helps, and if not, I'll drill a small hole in the lid and let you know how it works out. Thanks again.

 

Paul

[inTank]

So, with the lid firmly in place, skimmate is produced?

 

Yes, never had an issue in the past with this. Unless you have a super tight fitting lid they all just rest on the top so it is not an air tight seal. There could be other factors at play with the Tunze adjustments.

[Mushroom Boy]

It is a very tight fitting lid and does not simply rest on the top (i.e., it needs to be snapped into place). Think I should try drilling the small hole?

[paneubert]

I would say yes from my experience with random skimmers (not that one specifically). There has to be an air hole for it to work well or you will see the exact issue you are seeing.

 

Sounds like there normally is at least an air gap with that skimmer, and yours is just crazy tight/sealed.

[inTank]

I would say yes from my experience with random skimmers (not that one specifically). There has to be an air hole for it to work well or you will see the exact issue you are seeing.

 

only if the skimmer cup's lid is completely tight or locks down

 

It is a very tight fitting lid and does not simply rest on the top (i.e., it needs to be snapped into place). Think I should try drilling the small hole?

 

Yes, drill a small hole or sand down on one of the groves on the cup's lid so that it does not fit so tight.

[Mushroom Boy]

I ended up drilling a 3/32" hole in the lid of the cup. Worked like a charm! It's foaming nicely now with the lid completely in place. If I cover the hole with my finger, the foam recedes.

[inTank]

Awesome, good to hear. I was giving the go on a new production run of all cups today and had "secret" holes cut into the lid. Even though this sounds very rare with the laser it is time that we finally put a hole(s) in the lid.

[Mushroom Boy]

FYI, as of this morning, I've found that the 3/32" hole was not large enough. It allows enough air through, but over time, moisture builds up on the inside of the hole effectively sealing it. I'm going to increase the hole size incrementally until I find the right size. I've bumped it up to 7/64". I'll keep you posted.

[inTank]

Where did you drill the hole?

[Mushroom Boy]

Upper left corner...

 

[Mushroom Boy]

Quick update. 7/64" seems to be the ticket. It's large enough to allow any moisture build up to drain back out...

[Alkamist]

you should just put one in every corner if the lids too tight thats how my skimmers cap is