Too much pump, too little sump

[Cliff]

Hey folks, I'm here looking for help again. I have a 90 gallon 1/2 round tank, which greatly limits the space beneath the aquarium. The biggest sump I can fit is a 29 gallon. I have installed a 2000 gph external Reeflo Dart. I have plumbed the pump to supply both my PM skimmer and two 1" returns to the tank. I cant seem to get rid of the microbubbles. My overflow return is adequate, with dual 2" return lines. The issue seems to be the fact that I'm flowing 30+ gallons per minute through the sump.

It appears the flow through the sump is too fast to allow the bubbles to float at the traps (2). If anyone has any design ideas, I'm willing to experiment. I'm currently restricting the flow with a valve much more than I like, but it seems to be the only thing that works to keep micro bubbles at bay.

Is there something I can do in the overflow/return plumbing to discourage microbubbles? How far apart should the low/high bubble traps be for such high flow? Anything else I'm overlooking?

Thanks

 

[mariobrothersleeve]

Filter sock? Seems to work 4 me.

 

[MitchReef]

OMG..... 2000GPH in a 90G display!!!! A bit of overkill, don't ya think????

 

[MitchReef]

2 to 5 turnovers is normally considered the appropriate return rate....your total flow should be generated by powerheads / propeller pumps, etc in the tank....

 

[Cliff]

Yes, 2000 GPH may have been a bit ambitious - but the tank really has rocking current if I can get past the bubbles! I've tried a sock and 2 sponges.

 

[MitchReef]

You may not ever get the bubbles under control with that much pump....your flow should really be generated inside the tank....but I gotta admit, it is cool having massive flow!!!! My 75G had a 1000GPH return and an additional 5000GPH inside the tank! SPS just absolutely loved it....but I also ALWAYS had tons of microbubbles....

 

[Steveg229]

You could try building a bubble tower. I was having some micro bubble issues when I go sockless every once and a while, so I built this bubble trap. Works perfectly as all bubbles rise to the top and water exits the bottom. Might help...?

 

[Cliff]

Steve

Thanks for the idea. It appears you have some sort of media in the bubble tower. What is it? I have a similar tower, using a wide mouth 1 gallon jar to receive the return flow. Bubbles are forced up before the water is pulled under a sump panel. It also looks like you neck down the return line with 2 reducers. Why? What does this do?

 

[MitchReef]

I made one of those once and filled it with LR Rubble just to make a bit more of a torturous path for the water, thus stripping even more of the bubbles from it....I had the most luck of all using a PVC T...

 

[Steveg229]

+1 Mitch... Yes, I filled the tower with LR rubble. The reducers....well,...those were the parts I had on hand when I was changing the drain line. You generally never want to slow the flow on your drain line and I was concerned initially but it didn't cause any issues.

 

[Cliff]

So the verdict is in. Yes, you can have too much pump for a 29 gallon sump. I reduced from a 2000 gph reeflo snapper to a reeflo blowhole 1400. NO MORE MICROBUBBLES! And a silent pump. Happy, Happy, Happy.

 

[mariobrothersleeve]

Ive got the reeflo blowhole 850 running @ 680gph. I thought i had good flow!

 

[Sidekick41]

I'm new as well and by the talk here I take it micro bubbles aren't a good thing. Any reason other than they don't look good in the tank?

 

[Steveg229]

Nope, we just don't want them in the display tank.