Bubbles in the tank problem...

[hermit]

If you are following any of my other postings you will know by no whtat my newest creation is a micro reef tank which is housed in a All Glass 15 gallon designer tank (dimensions are roughly 13"x13"x20". I have a custom made sump underneath with a Belin classic and a corner box in the sump which houses any chemical filtration I would want to use... Problem is that I am getting bubbles back into the tank and it is not from the skimmer because I have turned it off to see if there are any differences.. The bubbles are occuring when the water which comes into the sump trickles through the chemical media to the rio which is below.. Now in hine sight I would have located the rio elsewhere but I am limited with regards to room... I have attempted to use some sponges in the bottom of the trickle area but it hasn't helped much. I did read out here about the glass idea in the sump which would be great if I had more room... Anyone got any ideas..

 

[dennish]

Originally posted by Hermit:
... Problem is that I am getting bubbles back into the tank and it is not from the skimmer ... The bubbles are occuring when the water which comes into the sump trickles through the chemical media to the rio which is below...
I have a Rio600 for circulation, and it came with a venturi air tubing thingy (sorry for the technical lingo), which will add air into the water outlet(quite a lot of air). I assume you do not have this attached, but I have noticed that if ANY air bubbles get into the intake (i.e. when using a sponge type algee cleaner under the RIO and any air bubbles from the sponge float up towards the intake) it will produce the same effect. Could you be getting air mixed in with water?
Another related experience I am reminded of, is after I learned that only the top 1/8 inch of surface water really gets oxygenated, I thought it might help if I positioned the intake of the circulation pump near the surface to move that O2 rich water around better, but the suction from the RIO600 that close to the surface created a tornado like effect that pulled LOTS of air in with it. I had to move it at least 3 or 4 inches deep before it would not (eventually) create a whirpool that would draw in air(bubbles). At that point I figured it wouldn't help much so I repossitioned it where it was to begin with.
Not sure if that will help much, but at least it gives you a couple things to check.
-Dennis