Closed loop air leak

[atkinsg]

I set up a closed loop on my 125 using a MAG 18 pump and PVC pipe. I am getting micro bubbles and it sounds like air is entering the loop at the pump connection(s). I used teflon tape in these threads, but I guess that wasn't enough.

I'm would like to know what other people are using to prevent air leaks in their closed loops.

[mfinn]

I'm having the same problems with a closed loop on my tank.
I have tried to retighten all the connections and even rubbed a little silicone on all the joints.
I thought I wouldn't have this problem if I used glued joints everywhere I could.
The next step would be to completely redo the whole thing.

[Ehgemus]

I had the same problem, I found out that my intake was to close to the top of the water, about 1' from the top of the water and it would suck air through the water into the intake, so I moved the intake down to 3" and that fixed it. You mite want to check that.:rolleye1:

[MayoBoy]

Also, what size is your plumbing? If you're suction is too small, you'll create microbubbles as the impeller creates a tiny vacuum and liberates air from the water.

[atkinsg]

Harold - My intake is a piece if PVC 18" long with holes dilled in the sides from the bottom to about 8" below the water line.

MayoBoy - The plumbing is 1"

[MayoBoy]

Double check your threaded fitting - drip some food coloring around the suction fitting and see if it get's sucked into the system. (It's only going to be on the suction side - if it were a pressure leak, you'd have water all over.)

If that checks out OK, I'm going to say that your suction is too small (I'm going to say that even if it doesn't check out). You're at 30 GPM so your suction should be 1-1/2" minimum.