Plumbing an external pump

a little teflon tape wraped around the pipe before you snug it together should do the trick.

So I am getting the bubbles about once, sometimes 2 times, a min with the teflon tape on the four connections and the others are glued. Any way to figure out where the air leak is coming from? I was thinking of just using silicone on the outside of the 4 that I don't want permanent? Could there be another cause of the microbubles? I am not sure if they are being fed from the sump skimmers and then released when they build up in the u tube. Seems unlikely to me though. The skimmers have baffles and there is filter media in between the output and the return pump.

You could turn off the skimmer for awhile to see if it is the cause.

How many bends are on the intake side of the pump, and what size pipe?  if it is too difficult to pull through it will cause cavitation which will cause air bubbles too.

The pipe is actually 3/4 inch.

All this talk has me thinking about how I want to plumb my Iwaki 40 on the new 90g (see other thread).  To conserve floor space I may want to plumb the pump over the sump on a small shelf.  I can bolt it down with stainless or nylon screws so it can't fall in and I have this sweet check valve that should keep it primed. 



I was thinking of putting the check valve in the return chamber with a screen on it, up to a union  then to an elbow on the intake side.  The output side would have a union followed by a ball valve to shut it off to clean the pump, then it would have a wye to go to each SCWD.

Anybody see any problems or concerns?

Thanks,
Fax

OK, I think I owe Adam, Mike, Fax, and Dion a beer.

I ripped off all the silicone and teflon tape and glued the pvc. No bubbles.

It will not be coming out any time soon though. Thanks Guys.

I'm glad it worked out Jeff!