Nano DOC problem

[Opus123]

I bought a used Nano DOC skimmer from a local DFWMAS member a few months ago. I love the skimmer/pre-filter but I can't regulate the bubbles in the skimmer. Even with the blue screw screwed all the way in the bubbles are all the way to the top of the collection cup and it fills up with water in a mater of hours. While searching tonight I saw a post where someone mentioned that units had a screw that was 2 short. Is this true? I couldn't find anything else on this other than that one post. If true, can I buy a replacement screw from Home Depot or do I need to order one from Tunze?

Thanks in advance for any help. By the way, I've been using it with small piece of foam stuck in the air intake hole and it skims but I have no control over the bubbles.

 

[rvitko]

The screw isn't too short, that was my earlier hypothesis but I have been assured that that is impossible and the factory has convinced me that is the case as the assembly jig would not allow that to happen. The problem is the screw is too narrow, or the hole is too wide, depending on how you look at it and air is bypassing the thread. Even though our hardware stores offer screws and taps a 4mm or 5mm and that screw is labeled 5mm. It is actually 4.9mm and on an industrial level screws come in fractional mm. This is done to ensure a smooth movement. The gap is so tight in tolerance though that if just a fraction off some air by passes the screw. The fast and easy solution is to use the shorter 5mm screw that came in your hardware pack for mounting to a horizontal brace, screw it in slowly and cautiously as it is a full 5mm, and you will notice the fit is much, much tighter.

 

[Opus123]

Sorry, I should have been more specific. This is the reefpack 200 so it uses the magnet. I wasn't given any other hardware when I bought it. Would putting some teflon tape on the blue screw accomplish the same thing as using a new screw?

 

[rvitko]

If you PM me an address I will send you a couple screws to try. Teflon tape may or may not work. The air comes in from the back, the screw is covering a hole and as you back it out you expose the hole. The tape would have to be near the tip of the screw and if you try it I would just do one single winding.