Can't stop micro bubbles

[LeeAnn Terry]

A few weeks ago, my return nozzles suddenly started pushing out tons of micro bubbles. Before that, it was always crystal clear. Now it looks like a snowstorm! Micro bubbles are even collected on bottom of return nozzle.

I've read articles, watched videos & tried the following, all with no effect:
- reduced surface agitation
- turned off skimmer
- turned off gfo/carbon reactor
- cleaned all filter sponges & socks
- made sure all PVC connections are tight (there is no salt creep on pipes)
- there are no bubbles on water surface of sump return section
-replaced loc-line return line & nozzles
- cleaned return pump & propeller

Its a 150g tank with sump & external return pump. The sump has 3 over/under baffles between skimmer & return section. All hard pvc in plumbing, no flex tubes.

I turn off everything when I feed. When it comes back on, the micro bubbles are minimal, but gradually builds back up.

I assume air is getting in the line somehow, but I can't find it. I am so frustrated at this point.

Any ideas of what else I can try? I'm stumped as to why it suddenly started & how to stop it.

 

[Idoc]

Is there a valve between your pump and tank on the return line? Could be a tiny crack, or faulty valve starting, if so. Or if you have a union fitting, maybe a leak there. But, it sounds like it's definitely a small leak somewhere along that line.

 

[miPapareef]

Do you have a restriction on the input (suction) of the return pump? A valve, blocked filter screen, sponge, or anything else that could make the pump cavitate?

 

[LeeAnn Terry]

This is a picture of the return section of the sump. I have an external pump. The bulkhead in the sump is on the far end. I put a course media filter (the blue in sump) at the end of the sump where the bulkhead is to keep cheato from getting in the return line.

There is one on/off valve in the line from the bulkhead to the pump.

It's been running this way for 6 months with no bubbles. It was a few weeks ago that it suddenly started throwing out micro bubbles.

 

[14 foot reef]

I'm not sure how it wasn't creating bubbles before. There is no portion in this design that is correct. I hate to say that so bluntly. i would look into a redesign of pump placement if possible, I would guess your loosing 30-40% of efficiency out of that pump, along with creating many many air suction points with that many glue joints and turns. Plumbing 101 would not have this as an option.

Another trick is to take a flash light and shine it in the sump water column right at the pump suction bulk head. If you see any bubbles at all going into the bulk head, your will have 20 times that after they are sucked through the pump head. Check there closely, there needs to be ZERO bubbles prior to entering your bulk head to pump. any bubbles at all will multiply after it hits pump head.

 

[T-5unsystem]

How many gallons are in the sump? Not how many can it hold, but how many are actually in the sump during normal operation?

IMO 3 over under baffles is excessive. I think fewer is actually better because it slows down the water and allows the bubbles to bleed to the surface naturally. Water has to move quickly through baffles, if its moving so quickly the bubbles don't reach the surface they can't escape.

Have you tried reducing the flow through the sump (use the output valve, not input) by 2/3 and see if they persist?
Have you resealed all PVC joints with some clear PVC glue? While messy, its likely worth it and you can use a cotton swab rather than the included swab to make it tidy.

 

[LeeAnn Terry]

Thanks for all the help! I finally got the micro bubbles stopped.

I used a flashlight like suggested, and could see tons of micro bubbles in the sump. I thought about the question one poster asked: was a filter or anything possibly restricting the flow to input side of pump. So, I pulled out the course blue media filter that covered the whole end wall of the sump where the bulkhead is (media keeps cheato from getting in return line), and bubbles immediately stopped.

Several weeks before the bubble suddenly started, I had added a bunch of pods to the tank. I don't know if they clogged that filter, or it was just time for to be cleaned, but once it was out, the problem was solved.

I dose 2 part and have a dual gfo/ carbon reactor. Don't know if I even need cheato at this point.

Anyway, thanks again. I was about to pull my hair out over this one!