Biocube blowing bubbles from the return...

[becact]

I have a biocube 14, with maxi-jet 900 and a Koralia nano. My return pump is blowing many tiny bubbles which float around my tank. Is there a way to stop this so I can have crystal clear water?

I have a heater in the 1st chamber, a bag of carbon at the bottom of the 2nd, filter floss on top of the carbon, and just the MJ900 in the 3rd chamber.

No bubbles come from the koralia, just the return. It's blowing out quite a few. My water levels back there are good, though I did do this mod because the MJ900 inlet was right up against the wall in the stock configuration (before on the left, after on the right):

http://i85.photobucket.com/albums/k48/bchandlerucf/pump.jpg

The bubbles come out in little bursts, but looking back there I can see no turbulence around the inlet or in the 3rd chamber in general. The water is probably 2-3" above the pump inlet.

[jkrentz2515]

What would happen if you moved the carbon to the little spot to the right of the return pump? Thats where my carbon is and I don't have any bubbles.

[2_zoa]

Well if the right drawing is the after, then I would suspect that you are forming a vortex if the intake is under water.

Solution- put more water in the tank. You are going to have to run the water level higher than the factory markings. Don't worry, the water will not run any higher in the display side of the tank. Just add some and you will see.:)

Wait, I read the last piece of your post. How old is the carbon?
I have had this happen just after I put in a new bag of carbon. It had to purge out the air, even after a good rinse. I still think a vortex is possible tho.

[becact]

thanks guys. The top of the water is calm in the 3rd chamber, but I will add some more water anyway.

This is a silly question- but does the water flowing over the top of the 1st chamber and into the 2nd chamber give any positive benefits? Does to water need to aerate or anything like in a freshwater tank? I'm asking because if I fill it right to the top, there will be no water cascade into the 2nd chamber.

[2_zoa]

As long as you have surface aggitation you should be good. I and many others have modded the rear sections. I scrapped off the paint on the back in the middle chamber and added a light, chaeto, and boosted the water level almost to the height that you speak of and.....bam a refugium is born.

I wouldn't fill it to the point of equal to the display. You are going to want some difference. I run mine just below the tray that distributes the water. Just high enough as not to hear any noise.