Small Sump Design to stop micro-bubbles

[kysard1]

My first sump is a 20H converted with a skimmer section and a return section separated by the over-under-over baffles. Even at 50 GPH my display gets filled with micro-bubbles from the sump.

There is a lot of mis-information on popular websites about how to design small sumps. An over-under-over bubble trap with 1" spacing does nothing to stop micro-bubbles.

I now have an empty 30x13x16" acrylic tank and will be adding baffles in an attempt to run my reef tank without micro-bubbles.

Elimination of micro-bubbles is paramount, if that means no refugium - so be it.

I have ATO so the return section need not be big.

I have a Tunze 9010 (5x5" foot print).


How should I configue this sump ?

[jcpatella]

Well, I have a problem with microbubbles as well. The baffles do nothing to help them. What I've done, and I have to clean it out regularly, is put a long sponge between two of my baffles. It helps with the microbubbles a lot. If it clogs up, the worst that can happen is that the water will skip the baffle. Also, if you put the sponge BEFORE the refugium, you wouldn't catch the stray pods making their way to the display tank.

[SDguy]

Something is not right. 50gph should not be taking any microbubbles with it through your baffles, if they are of any decent size. Are you sure there isn't a leak in the plumbing/return line?

[Spuds725]

Ditto-- where are the bubbles coming from??

From the sump inlet section?? skimmer?? Depending on the source will dictate the solution.

I ran a 15 gallon sump with 200 GPH and had no bubble issues... only a single divider between a fuge and the return section

[kysard1]

skimmer.

[Zucker26]

I did the same thing as jcpatella, and it works really well. If you're looking for a cheap solution, that's my recommendation.

[kysard1]

The bubbles go right thru the foam. I put in between the baffles .

A 1" space in between an over-underbaffle still has a linear velocity of 1 inches every 4 seconds. Trust me these bubbles are too small to rise quicker than 1" in 4 seconds.


My new sump will have a large space between the over-under. I am thinking 9 inches. This would put the downward linear velocity at around 1" every 8 seconds at 200GPH, almost half the downward force I have now at 50GPH.

.

[SDguy]

1" every 4 seconds is SO SLOW. Unless you're running glycerol instead of water, I don't see how bubbles are going through. But I guess I'm not there to see it.

[kysard1]

These bubbles are small, I clocked them rising in my display with no circulation at about 1 inch every 6 seconds.

[jcpatella]

The sponge won't stop all of the bubbles, but it will help gather most of them into larger bubbles and rise to the surface.