Help with micro bubbles

[rider]

I have just put this tank together and i am getting alot of micro bubbles. It looks like when the water comes out the 2 1" drains through the filter pad, then through the bio balls its creating alot of micro bubbles, which go over into the refugium, then over into the last chamber where there pumped back up into the tank. I have included some pictures so you can see what i mean. not sure if i am running to many gph through or what. I have a gen-x pcx30 which returns up through 2 3/4" pipes.

I tried using a overflow idea from the DIY forum. basicaly a 2" pvc 2 feet long with slits across. they are just above the water so it will skim off anything floating on the water. I tried turning the slits down so they were totaly submersed in water and that got rid of any sucktion noise i was hearing, but i realy wanted it to skim anything of the top of the water. I tried putting down spouts on the back, but It wouldn't keep up with the pump when the valves where wide open, so i corked the downspouts.

what do you think the best thing to get rid of the sucktion noise and the micro bubbles would be. I thought about putting a sponge in the last chamber were the water is pumped back up, that might get rid of the bubbles.

Any thoughts or ideas.

there are more pictures of it at http://jhansz.com/pictures/

[crvz]

You could try tuning the water flow down out of the pump. I often recommend somewhere between 4-6x system volume per hour. That may help (and as an aside, I'd really consider getting gate valves instead of ball valves for the return pump... the ball valves are not near as easy to fine tune, though it looks like you're already glued up!).

Other than that, consider making a bubble trap in the sump. Right now it looks like youre using just egg crate, which isnt doing anything for bubble control. A couple baffles installed before the pump will catch any bubbles and allow them to reach the water surface before going back into the return pump. You can see a bubble trap I built over in this thread (where the baffles in front of the return pump force water over the first, then under the second, then back over the third, effectively removing any bubbles).

Final (unsolicited) recommendation is to lose the bio-balls. They're just going to trap fish wastes and leftover food, providing an area for these organics to sit and rot. If this happens, you will have nutrient issues, often resulting in unwanted algaes or tank health issues. The sump looks good otherwise, but consider pulling those out.

[rider]

the egg crate material is just to dampen any noise from the motor. do you think it would help if i replace the bio balls with a sock, or would i still have the micro bubble problem? wouldn't be to hard to replace the valves. whats the benefit of gate valves versus ball valves?

what are your thoughts on the overflow?

[crvz]

Originally Posted by rider

the egg crate material is just to dampen any noise from the motor. do you think it would help if i replace the bio balls with a sock, or would i still have the micro bubble problem? wouldn't be to hard to replace the valves. whats the benefit of gate valves versus ball valves?

what are your thoughts on the overflow?

Eggcrate is what I call the light defuser you're using in the water between the macro algae in the sump. Even though the foam material would be similarly described.

A sock may help, but I'd really consider looking to install baffles to act as a bubble trap. Similar to the issues with the bioballs, the socks will collect wastes really quickly, but as long as you change them out every week you'd be able to control that pretty easily. A lot of folks will be 4-5 or more and just rotate them, throwing the dirty ones in the wash between uses (if you could change it twice a week, that'd be even better). The sock would definitely help with bubbles compared to the bio-balls, but it's hard to say you completely eliminate the problem with just a sock. A good start, though.

Gate valves are designed to give detailed control over flow. The ball valve should really be used more as an on/off valve, not something to tune in the return pump. Gate valves can be a bit tricky to find, I don't often see PVC gate valves at the hardware store, but places like www.savko.com will carry them. They are a bit more, but give you a lot better success.

[Loverotties]

Run the pipe down in the water(get rid of bio balls and eggcrate).

[rider]

did you have any thoughts on the over flow? how would i go about making it quieter. seems to work good except for the suction noise. I've tried using down spouts, but i didnt get enough flow. Any ideas?

[crvz]

A standpipe is the way to go, but sometimes sound is a result of high flow rates too. Another reason to dial back the pump (and add a gate valve ). A well designed standpipe won't limit your flowrate. What do you have in the overflow right now? Just the hole in the bottom? Search for "durso" standpipe, I think there's a website out there (found it; http://www.dursostandpipes.com/)

I wasnt really putting this together earlier, but if you're getting siphoning, that results in changing flow rates into the sump and increased air intake/micro bubbles.

[rider]

micro bubbles are completely gone. got rid of the bio balls, put in a sock. and just cause i didn't want to have any issues with bubbles again, i put a sponge in the last chamber where the pump is. thx, guys.

[crvz]

glad it's fixed! just make sure to clean out the sock and sponge 2-3 times a month and you should have no problem with that solution.