Where could microbubbles be coming from?

I just switched out my sump and return pump and cut my returns from four to two (I had four total bulkheads in the back of the tank, I plugged up two). I was still getting microbubbles with the old pump but it was dialed back some (MD 2400) and had more plumbing twists and turns to it so I figured that's why I had a bunch of bubbles flooding the tank. Now I moved to this Quiet One 6000 pump. Now I have just two bulkheads it's sending water through but I am still getting a flow of microbubbles coming through both bulkheads. I have the pump running wide open and even have a long round filter sponge over the intake of the pump and I still get the microbubbles. Where else could they be coming from?? The return section of the sump isn't overwhelmed by bubbles, just a little from the other two parts flowing down over the baffles into it and you'd think the sponge over the inlet would take care of those.

I only have one T in the plumbing, that's splitting the water in two straight out from the pump after my gate valve. I then have straight pieces form the T going to 45's and then into nylon reinforced flex hoses up to the bulkheads, then a 90 into the bulkhead. Only thing I can think of is the flew tubing, you can see dark spots in it. I'm guessing it's spots of algae or something and maybe the bubbles are coming off of that? I have no clue. Maybe since the pump is brand new it's still getting slimed up and will eventually stop shooting bubbles out? This really kills the look of a tank.

can you take a pic of your sump?

emmett0122 said:

can you take a pic of your sump?

Click to expand...

+1 .... Water Level in Sump?

I actually uploaded three. One of the sump in general, one of the pump fully submerged under water with sponge over the inlet and one more of a straight out shot of the bubbles coming out of one of the two bulkheads.

Right now there is 9" of water in the return section. I always try to keep it relatively full and do have an ATO kit. Just haven't had a chance to start it up yet. Will probably do so today.

It appears your skimmer is discharging very near your return pump, is that correct? Do you still have a lot of bubbles with your skimmer off?

Are all your fittings glued? Just want to be sure you are not sucking air from a loose fitting.

The skimmer discharge is in the same chamber as the skimmer and there's a wall between the two so no, it's not discharging in the return chamber. I haven't tried turning the skimmer off yet but considering the discharge is in the skimmer section, I don't think that's the problem.

I do glue all my connections. The only non-glued parts are the outlet of the pump and my hose barbs that I have clamped on. I would think that if they are letting air in, I'd have a leak, no?

One thing I do wonder is I notice the little black o-ring that's around the outlet of the pump. You can see it in the pic. I don't know what that's for. I got the initial adapter in very good but I didn't go as tight as I could so that I didn't crack the adapter or even possibly ruin the pump threads. I wonder if you're supposed to screw the adapter all the way down and this is meant to be a seal of some sort? It's all under water though so I don't think it would be taking in air whether it was meant to seal it or not.

A few points and a few questions. First....normally you see the three baffles between the skimmer and the return. That is the bubble trap. So from your picture it appears you have the fuge and skimmer sections reversed. If you have a single baffle between the skimmer and the return you want to make sure when the water flows over the baffle that it is not creating bubbles that are then sucked into the return.

I don't see any flow in the fuge/live rock area.....is this correct?

I could swap sides with the skimmer and the fuge section and try that although I'm not sure it would make a difference. Anything might do it at this point though. Looks to me that the water falling into the return section is making a lot more bubbles falling over into the return section than the skimmer side. I have to set up my ATO tonight so maybe in doing all of that I'll swap the skimmer and fuge side and see if that does anything at all.

I have a dual durso setup running so I have one overflow drain going to each side. So yes, there is flow going to the fuge side.

this is the way most sumps are setup first part in drain from the tank then bubble trap then fuge and for me i have a second bubble trap then the return pump no problems with bubbles

Here's what I know so far. I turn off the skimmer and back the pump down about half way and I have no bubbles. Skimmer on, I have bubbles regardless of flow of the pump. So tomorrow I will try to switch sides of the skimmer and get the discharge of the skimmer on the very end of the tank. That way the bubbles will need to go through the baffles before they hit the pump. I'll try it out and post the results.

Ive been thinking about this for a while. Did u used a slime coat accelerator or protector in the water?

I haven't put any chemicals whatsoever in the water since the day I started the tank which was about three months ago.

I swapped the sides of the skimmer and fuge and I still have to turn the pump down about half way to avoid getting a steady flow of bubbles and even then, I get a small amount but not enough to bother me. Now that I see I have to dial it back about half way, this pump puts out 1664 gph max and that's before you add in the head and plumbing. Am I still getting enough flow out of it to run this system efficiently? I have a 40 gallon sump with an ASM G2 skimmer.

If you have the 3500 pump on the skimmer then it is rated for 350 gph. So, I would dial the return down some and then provide addition flow with Power Heads.

Yep, it has the 350 pump on it, just want to be sure there's enough flow for the sump to be running efficient. Powerheads are next on the list and I should be getting them soon. It's dialed back maybe half way and it's looking a lot better so I'll take what I can get.