Microbubble Nightmare

[kdrake]

I just built a new sump for my 90 gal RR. The sump will hold about 25 gal at full capacity. From the tank I ran 1 1/4" clear tubing with a ball valve to control flow. The water feeds into an area about 3" with a 1 foot baffle. It then flows over the baffle into a larger area of about 1 cubic foot of space. It then flows under 1 bubble baffle ( about 6 inches from the bottom), over one baffle and then under the last baffle (again about inches from the bottom) into the area where I have a Quiet One 6000. The return line is 1" clear tubing with a ball valve in the line.

I cant seem to get the bubbles to stop going into the tank. I have tried to "tune" the system to allow the input(from the tank) to equal the output (the return to the tank) of the pump. Everything works great until the water in the sump equalizes(becomes level across the entire sump). That is when the bubbles start rolling down the input tube.

I know this is long and somewhat complicated to visualize and I have read as much as I know how to solve this problem on my own, but I need your help. Any suggestions would be appreciated.

Thanks

 

[Sam]

I think that if you are seeing MBs the issue is that you are pulling air into the pump. Now unless you have a leak in the system, the other explanation is that your input to the pump is not adequate enough to support the output. So there is a strong enough vacuum for the pump to pull more water than is being supplied. This is what creates the microbullbles. I would suggest that you use an adapter and change the return from the pump to a 3/4" line. Also make sure that the inlet to the pump is at least 2 1/2 " below the surface of the water. I read that you see bubbles coming down the input tube. This suggests to me that the air is being pulled in at the input intake. How is this set up? Make sure that this is well below water. You did not describe how this is set up. Make sure your inlet intake in the tank is large enough. HTH 8)