Microbubbles help

So I thought I had a problem with sand particles in my tank. After paying close attention to my tank, I realized it was microbubbles. There are no bubbles in the sump, that I see anyway. So I thought it may be in the return line. I turned the return pump off about an hour and a half ago, to see if the bubbles would go away. The only movement in my tank right now is two powerheads, and the bubbles are still in there. Should I just give it some more time, to see if the bubbles will go away, or should an hour and a half with the return off be plenty of time? If it's not the return, what could it be?

 

A pin hole in your return line
Flow to high through the sump
Powerheads to close to the surface
water level in return area to low

Those are a few things to check. Fixes are pretty easy.

 

Could be nitrogen bubbles from your rock.

 

I thought something like pinhole leak through return. That's why I turned the return off, but after 2 hours, I've seen no reduction in bubbles. I just moved my powerheads a little lower, to see if that was it.

Would this be bad? Any fix for it?

 

Bump

 

How old is the tank setup? I see someone suggested bubbles from the live rock and that can happen in the early stages of an aquarium.

 

I've had the tank set up for about 2 months, but it was set up for around 3 years before I got it. The water quality was horrible when I got it, now I'm slowly getting the parameters back to normal. I also added around 50-60 pounds of LR when I got it.