Microbubble problem

[unknown]

Hi everyone, I can't seem to beat this micro bubble problem and could use a few extra brains working on it.

So I'll add pictures to clarify everything but I'll lay it all out first
Return section of sump has a bubble trap/baffle with bio balls on one side, carbon on the bottom, and an open chamber on the side with the return bulkhead. Water goes from the bulkhead threw 3/4" tubing to a Mag 9.5 they pumped up threw a ball valve, check valve, union, T fitting(other side has a ball valve and a cap), reduces down to 1/2" after the T. THen it goes threw a SLP/MPT to a FPT/SLP to a 1/2"-3/4" 90 insert into tubing that connects to a insert 90 that is screwed into the bulkhead.
The skimmer is on the opposite side of the sump from the return and there is no turbulent water at all in the sump.

I have checked, double checked, and tripled checked all the threads for tightness and reverified that all hose connects are tight. I don't know what I'm missing here.

Help is extremely appreciated.

Thanks guys
Vince.

 

[unknown]

 

[bang guy]

My initial guess based on picture 1 is that the combination of an elbow right off the bulkhead and stepping the diameter of the pumps intake down from 1" to 3/4" is restricting the intake waterflow too much.

This is easy to test for - Turn the ball valve until it restricts the return to about 25%. If the bubbles stop then I might be right. Restricting the input to a pump can cause cavitation.

 

[unknown]

The mag 9.5 has a 3/4 inlet and outlet.

I tried restricting the flow on the return pump and I didn't see much difference. Could the check valve be creating turbulence inside itself and causing the bubbles? I'm trying to figure out how the air is getting into the line?

 

[unknown]

You think maybe were I neck down the pipe from 3/4 to 1/2 then back to 3/4 is were the issue stems from?

 

[pegasus]

You think maybe were I neck down the pipe from 3/4 to 1/2 then back to 3/4 is were the issue stems from?

That would only cause a reduction in flow by creating back pressure. I don't think it's going to be in your plumbing. The only (logical) way micro bubbles can make it into the tank is if the pump is taking in air... either sucking air at the intake, or bubbles in the water coming from the sump. There's positive pressure on the outlet side, which would only result in water coming out in the event of a leak. It CAN, however, suck air in on the inlet side of the pump. That narrows the suspect area down to the space between the intake side of the bulkhead, and the intake of the pump. I don't see a clamp holding the hose to the elbow on the bulkhead, nor do I see a clamp on the hose where it's connected to the pump intake. How is the hose attached to the inlet? I also see some white stuff where the elbow goes into the bulkhead. What is that? If it's salt, then you have a leak there. If there are no air leaks on the inlet side, it has to be bubbles exiting the sump. If you have a piece of coarse foam pad, you could try setting it up in front of the bulkhead as a bubble trap and see if there's a reduction in micro bubbles.

Note: I'm not a professional plumber, but I've dealt with a lot of sh*t! LOL!!!

 

[pegasus]

A picture of your sump, especially the bubble trap(w/bioballs and carbon) may also be helpful.

 

[unknown]

So I changed out all 1/2" piping to 3/4 which removed 2 threaded fittings that potentially were allowing air into the system but nothing changed. Here are a few pics of the sump. The water level is usually a bit higher but even at this level the return BH isn't drawing a syphon from the waters surface. Also I added 2 hose clamps on the return pumps suction side like you suggested pegasus but didn't see any improvement either.

 

[pegasus]

Are those bubbles on the (underwater) sides of the return chamber? Did you splash water on the (above water) sides in the return chamber, or is it like that all the time? Not sure why you have bioballs in a wet sump, as they tend to work better in a wet/dry sump. They're kind of 1970's, anyway. If you want more, I have a box full of them in my basement (came with a used tank). If you have plenty of live rock and sand, you don't need them. A foam pad would serve a better purpose in that space, as it would trap any large particles before they get blown back into the tank, and help keep your pump clean longer. The foam would also help trap bubbles that makes it to that side of the sump. Did you try putting a piece of coarse foam in front of the bulkhead where the water exits the sump? A few tiny bubbles entering the pump will get churned into massive amounts of micro bubbles by the impeller.

One thing I haven't asked about... the skimmer. Are there a lot of bubbles coming out of it?

 

[unknown]

There not bubbles in the return side, more like particles from the bottom of the sump. The water turns over pretty quick and kicks up the some stuff that sits on the bottom of the sump.
Theres no splashing going on in the bio-balls side of the chamber it just has a quick current. As for why I use the Bio-Balls, It's to give me real-estate for bacteria/algae to adhere to and help cut down on toxins in the water.
I did put the coarse foam filter that comes with the Mag Drive in front of the BH return, haven't really seen a noticeable improvement though.
As for the skimmer, it's a NAC7 and isn't releasing any bubbles what so ever into the sump.

 

[unknown]

Bump for any new ideas?