Lots of tiny bubbles in new pump set up

[rgs777]

I just had to replace my main pump on my 180 gal. The new pump is a little bigger and the input/output connections are 1" where as my old set up was 3/4". So I've had to do new connections everywhere to accommodate this. I used teflon tape on all screw in pieces, really tightened down the hose clamps where used. Turned on pump, tons of tiny bubbles. I then used aquarium silicone gel around all joints I could find. Still bubbles. Any suggestions?

Thanks.

[BeanAnimal]

The silicone usually does nothing but make a mess :)

There are two possible problems.

1) A leak small enough to suck air in, but not allow water to leak out. I suggest using teflon paste instead of tape. It will work much better for this application (and most threaded PVC applications).

2) The pump is cavitating due to the suction side being too restricted. This is easy to check. Use a valve or other means to slightly restrict the output of the pump and see of the bubbles stop. If they do, then the pump is being starved for water.

Let us know how it goes.