return pump and microbubbles?

[jck09]

alright peeps i need some help. i have a 90 aga reef ready. my return pump is a mag 9.5. i have had microbubbles in my display for about as long as i can remember. i thought that it might have something to do with my plumbing. originally i had my overflow split to skimmer section and fuge. both then overflowing into my return section. i redid my plumbing last night and now overflow goes into skimmer section then overflows into the return section. my fuge is fed by the return pump rather than the overflow (t'd off the return plumbing). this did not help the micro bubbles. my other thought is that my return pump may be too much and just pushing microbubbles through the sump. sump is a 55 gal. would a mag 5 be better to use as the return rather than the 9.5.
thanks. john

 

[AZDesertRat]

Do you have multiple baffles and how are they configured, as in over under over? A 9.5 should be fine with a 55G sump, I use a OR 3500 which is almost identical flow in a 30G sump myself and have no microbubbles.
How submerged is the pump and how is the return plumbed? Do you have a ball or gate valve on the discharge and is so does throttling the pump down decrease or stop bubble production?
Have you tried shutting your skimmer off to see if it is causing or contributing to the bubble problem?

How big is your return section and does the water cascade down over a baffle carrying bubbles down to the pump suction? Do you have a filter sponge or any other restriction on the suction side of the pump which may be causing cavitation?

 

[ReefGeezer]

Sometimes there are tiny air leaks between the return pump and the display tank where hoses connect. I use hose clamps all connections between the pump and the tank.

 

[nater]

i think i am in the same boat in ways. i thought it was my sand sifter , but i don't think thats the case anymore. i also have a 90g. it's a tech tank though. just trying the advice from azdesertrat , and turned off my skimmer. it is what has been causing my bublles, so thanks AZ. lol , i redirected the out flow a week ago , guess its been throwing bubbles into my chiller pump and right over to my return pump. gosh. don't know why i didn't think of that earlier. love this site.

 

[jck09]

i think the micro bubbles are coming from two places. my fuge section sends water to the return section falling about 5 ". also from my skimmer. my baffles arent set right. i only have two rather than three (under - over). i think ill be adding some baffles this weekend. thanks
john

 

[Harry_Y]

Slowing down the flow through the sump tends to reduce the micro-bubbles.