Downscaling pump?

[alexwolf]

I am having a problem. Microbubbles. All over my tank. If i slow down the flow, they go away. Therefore, i am thinking this:

get rid of the huge pump, get a smaller one, and concentrate on flow in-tank.

2 tunze 6100 for flow, and a pump like the iwaki 30 or 40 that josh mentioned. anyone see any problems with this?

[NaCl_H2O]

Alex, any idea where the bubbles are coming from?
How are you "Reducing" the flow now?

If your current pump is cavetating, reducing the flow by closing down a ball valve could be changing head pressure and getting rid of the bubbles. A new pump of lower flow, running wide open, may still cavetate?

Are the bubbles coming from your skimmer, leak in a pipe, or a **** in your sump? In which case a lower flow return pump might give the bubbles time to escape before reaching the pump?

I would buy a Blueline/Panworld before an Iwaki - basically the same pumps, but a little cheaper.

IMO I like a lower flow rate through the sump and more "In Tank" flow. This gives your skimmer, etc. more time to work on the water passing through the sump.

[alexwolf]

i shut off the skimmer and it didnt make a difference (guess i built it well :)) I am slowing it down with ball valves.....i dont think its cavitiating because the bubbles are all the time.

[NaCl_H2O]

i shut off the skimmer and it didnt make a difference (guess i built it well :))
Probably just lucky ;)


I am slowing it down with ball valves.....i dont think its cavitiating because the bubbles are all the time.

Is the ball valve on the inlet or outlet side of the pump?

I would determine the source of the bubbles before you replace something that may not fix the problem???[/quote]

[alexwolf]

outlet, 3 ball valves on individual outlets. Doesnt matter which is open or closed.

[NaCl_H2O]

outlet, 3 ball valves on individual outlets. Doesnt matter which is open or closed.

Oh, so you are not restricting flow out of the pump, just diverting it elsewhere ... right?

If so, try closing them down in a way to create some back pressure on the pump (but not too much) - you should be able to hear the pump start fighting against the pressure. Basically this adds head pressure on the outlet side of the pump. If the pump is cavetating, that should reduce the amount of bubbles being created.

[alexwolf]

same amount, i have reduced it to one outlet with not a lot of flow.....same amount

[NaCl_H2O]

He's running a Sting Ray return, so getting what like 2500 gph through the sump? IMO that's far too much.

:o If you have a dam in the sump, that's probably your bubble source and the brisk flow is just carrying them into the return pump???

Solutions:
1) Smaller return pump + closed loops/Tunzes
2) BIGGER sump :-D
2a) and another show tank :-D :-D

[alexwolf]

yeah, i think i will try the iwaki 70 that i have here, wont be too hard to try! love those unions :)

[GaryP]

Did you teflon tape your unions when you hooked everything up? When I put my Iwaki in I didn't telfon the threads in the unions and it sucked air. They can act just like a venturi and suck air through the threads.

Gary

[don-n-sa]

I run the sequence barracuda on my 240g which has the same flow as Alex's pump, it is just the newer model. I have ZERO microbubbles.

Alex, like I told you just be patient...sometimes microbubbles go away on their own after the slimecoat forms on all your new plumbing.

[PsychFish13]

I never use ball valves for this reason. I have had much better luck with gate valves and they give you tons more control over flow rates.

[captexas]

As long as all the joints in the pipe are sealed well, it doesn't matter what kind of valve you use. If there is any bit of a hole in a joint, pushing that much water through it will create a suction to where air could be pulled in, therefore you get microbubbles.

I would say if you have a handy extra pump around and it's easy to swap them out, give it a try. If anything you will at least narrow down the possible source of the bubbles. If you have a closed loop, use the bigger pump on it instead of your sump return. Also, give it some time as Don said, your joints may seal up or you may have an air pocket in one of your lines due to opening and closing valves. If the problem continues, you need to find where the system is sucking the air in from.

[georgeortiz]

I was having problems with microbubbles in my closed loops. One day I went ahead and started looking at all the plumbing, used marine goop on every joint and VOILA no bubbles. You might want to try this before you go and buy a new pump. You have a heavy flow rate but, maybe it is just the plumbing letting air in. Since they are small bubbles it is probably a small crevice or joint that is letting in a miniscule amount of air into the system.

[alexwolf]

another concern of mine is the splash from the sump. I feel that less flow will fix this problem.

[dan]

or get a bigger sump. i have the same pump but my filter is 8' long so i hope the bubbles will leave before they can reach the pump. plus the filter is in two sections. like in a L shape. still haven't pluged her in yet.

[alexwolf]

LOL
you just built me this sump!!!

[NaCl_H2O]

plus the filter is in two sections. like in a L shape. still haven't pluged her in yet.

Hum, sounds similar to one of your customer's systems ;)