Redid plubming - now I'm getting massive micro bubbles

Okay, many of you know i recently lost a return pump due most likely due to an errant snail. I addressed the snail issue with a prefilter sponge to keep those bastards out of the pump intake. The other issue was it was a total son of a $%@&^$%@@#$ getting the old system pump out and the new system pump in. Because of this I decided to redo the plumbing for the return pump.

The first thing I did was add a union directly on the output threads of the pump to make it easier to disconnect the pump from the system manifold. This is only half the battle though, as I had nothing to shut the water off from the sump when disconnecting the pump intake (its an external pump). I called up BRS and ordered two of these
1? Cepex Ball Valve - English
(one for the system pump and one for the skimmer pump)

So, I connected this ball valve to the threads on the pump output. Because I only had femail hose barbs, I used a 1 inch male nipple to connect the hose barb to the ball valve, there is then a 2 inch section of vinyl hose, and then the hose barb coming off of the sump. I had micro bubbles as soon as I refilled the empty sump and started things up earlier this week.

Today I sat down and thought about it, and the only thing I could think of was that the seal on the ball valve wasnt tight and needed adjustment. I ripped everything apart and tightened the seal, then put it all back togeter. Crossed my fingers and plugged it in, and I'm still getting bubbles. It't got to be coming from the new plumbing somehow for two reasons:
1) its the only thing thats changed
2) you can see a massive stream of micro bubbles coming out of the return lines in the DT

So - what am I missing? Hopefully I get some good ideas - because between this, losing a system pump, and a skimmer pump thats making odd noises and needs to be torn down, I'm about ready to take the tank down for good

Next question, how bad are micro bubbles for fish /coral / inverts? Can this wait till after Christmas to get resolved?

You obviously have an air leak or large bubble somewhere. I would disconnect the pump and shake/spin it around to make sure there's no bubbles trapped in it, just in case, and then reseal every joint above the pump. Air is getting in the return lines somehow, even if it's not leaking any water. Is the hose completely clear? If you see air bubbles in the entire line then you know the problem is before that. I would check all the connections in and around the pump and just redo them.

What kind of pump is it? And where is the prefilter sponge? It might have air trapped in it as well.

I was thinking the same thing, but the only place I could think of where air was getting into the line was the ball valve / union on the pump intake.

The pre-filter sponge is in the sump underneath the bulkhead intake. The bulkhead has a 90 degree elbow in side the sump as the intake, and then exits the sump via a 1" hose barb. From that hose barb, there is about 2 inches of clear vinyl tubing, then the hose barb that's attached to the ball valve. The water in that clear vinyl tube does not have bubbles in it, neither does the line coming off the pump that goes to the refugium.

The pump is external, so any time I kill the power to the pump and close the ball valves off to remove the pump the water drains out and its full of air, that's never caused a problem before, other than a few large bubbles on start up. I'll just have to start on the pump return connections tomorrow. Its a Pan World 100PXX
http://www.bulkreefsupply.com/store/...p-1270gph.html

The only other thing I can think of is I scraped all the green fuzzy nasty algae out of the rim of my overflow boxes, but I don't see how that would cause these micro bubbles

OK, I know a silly question, and don't be offended at all, but it does need to be asked.

You used PVC glue correct?

Also, are the little O-rings properly seated in the unions?

Other than that, I got nothing. Just try running it for a while to see if the air gets worked out of the new plumbing.

It's a ball valve and union in one, so I did not use PVC glue, if I did the that would make the union worthless wouldn't it? The o ring was definitely sealed - and I tightened down the ball valve as far as it would go

I've re-done all the connections on the intake side, i'll have to redo the connections on the return side to see if that makes a difference

How about Teflon tape on the threads?

Yep, everything with threads was taped

Just throwing it out there... I am not sure if it is possible with your pump set-up but if you traced everything and there are no air leaks, how about impeller cavitation?

I'm not sure about inpellor cavitation, but the pump is brand new and only has about a weeks worth of run time on it

Hey did you resolve this? I'm still a beginner. I did experience bubbles on mine, until I moved the return pump away from the skimmer. But since yours is in the same position, I can't think of why it would have started with a new pump, all other things being the same as before.