Above-tank fuge--microbubbles

[catdoc]

I set up a 29 gal fuge last night that gravity feeds back to my 125 display with a HOB Lifereef overflow. It's a very simple system, no baffles; more like another display tank with a different biotope I guess. Anyway, I'm getting too many bubbles in the larger display tank but I don't know how to fix the problem. I want the fuge to return directly to the display b/c the purpose is pod production to feed my fish.

The fuge is fed by a MJ1200. The overflow drains into the tank via a 1" pvc run that drops 18" from the bottom of the overflow box to water level in the display. The pvc does continue about 6" under the water level.





Possible causes of the bubbling: need a smaller feed pump? Less pvc under the water's surface in the display? Smaller diameter pvc? Some kind of bubble trap in the display? There are no bubble issues in the fuge, just where it is dumping into the display. (BTW, the water level in the fuge IS level, it's just distorted due to the camera angle.)

For now, the fuge isn't being fed by the display so there is no overflow right now. I am letting it cycle since I added LS, rubble and some grunge to seed the new sand and I don't want it trashing the display tank. The fuge is still very murky, as you can see. The water feeds into the fuge from the middle of the display to the left end of the fuge, then dumps almost straight down back into the display at the overflow. Hope that all makes sense.

thanks!

[catdoc]

Anyone? Is my question too easy or impossible to remedy? I've tried using the search but can't seem to hit on the right combo of keywords to get the answers I need.

[fishfeeder]

I'm sure it maybe coming from the siphon box you have on the fuge...maybe try to add some type of foam or mesh to the end of the pipe in the display tank to help burst some of the bubbles or shorten the pipe so they rise quicker.

Not really sure maybe someone has done this before could help!

[Misled]

To stop the bubbles Put a trap in the drain In other words let the pipe go below the water level about 2 in. With 2 elbows back to back and a peice of pipe bring the pipe about 1 in above the water level. Put a peice of foam from an overflow tube around the top of the pipe. Make it just touch the water. Rinse the foam every couple days.

[eng94]

i had that set up on my old tank what i did was put an elbow on the pipe entering the water half in the water and half out of the water it worked like a charm bubbles break right at the surface.

[catdoc]

I'll try reworking the end with the elbow at the water surface. I want to avoid the foam/filter pad at the outlet b/c that would defeat the purpose of using the fuge to feed the tank as it would trap all my little critters.

Thanks!

[mb5322]

I had the same problem with my 75 gallon fuge, the only thing that worked was to put a ball valve on the return from the fuge. Then adjust the ball valve to slow the water down and to raise the water level in the overflow box itself so it doesn't crash over the divider piece.

[waldomas]

If youre fuge flow is slow enough (something slower than a maxi1200), it seems you could put a longer return pipe into the main (deeper), so the bubbles wouldnt leave the pipe. Would you have to put a syphon break type hole in the top (to let the air out)? Would any flow be enough to "blow out" the bubbles (into the main)? Are the bubbles causing excessive salt creep? If you didnt want to use a sponge, perhaps you could built a liitle box to place over the return to confine the bubbles...keep a lid on it so to speak.

I too have an above main fuge. I too have bubbles from my return, but...
it is in the back corner and I covered that with a peice of plexi to help with the salt creep. I am going to try to drill a hole at the top (above the water) to see if that helps. My pipe goes down about 15 inces below the surface. I hardly have any flow at all through the fuge. My fuge is drilled in the side and too much flow could overflow my fuge.

Good luck and keep us posted.

[catdoc]

I reworked this from a couple angles. I powered down from the MJ1200 to a MJ900. Next, I cut off about 6 inches of the pvc return and added an angle (135 degree?) with about 3/4 of the opening under the water and the rest open. That's helped considerably, but I still have some microbubbles that I need to get rid of. I may try taking the 1" pvc draining the overflow down to 3/4" and see what effect that has.

Other than that, I love watching the fuge. I've been transferring critters from my basement fuge up to this one, so now I can watch the life. I've got some chaeto, halimeda, ulva and gracilaria with loads of bristleworms, copepods, amphipods and the tiny little shrimp-like guys (what are those called??). It's almost as much fun to watch as the main tank, which was why I wanted to set it up. I think fuge tanks are as interesting as the reef display tanks. Fun!