micro bubble battle

[fatoldsun]

Question… I guess this is ok in equipment but to be honest I wasn’t totally sure if it belonged here or new set-ups. Anyway, I have a TON of micro-bubbles and I’d like to address it if possible. Current set up is a Mag 9.5 return which I suppose is the culprit. Otherwise my sump is set up with a skimmer --> return <-- refugium. I have baffles between my skimmer and the return and I have an experimental bubble-trap in my fuge.
Here’s my sump layout

And this is the design for the fuge bubble trap – minus the live rock rubble. Redfishbluefish who was the originator of this design suggested that the rubble would be a detritus trap and I didn’t want to have to take it out and clean it constantly so that was left out (probably half filled with sand from storms anyway)

So the question is:
Is the Mag 9.5 the source of my bubbles? I avoided any 90 degree angles on my return plumbing – hopefully you can see that in the pic. Some bubbles to make it through the fuge trap but nothing too terrible. I do get some bubble going from the fuge into the return where that cascades down, but again, nothing terrible.

The setup is finally established so I’m not sure I’d want to tear down the sump and start over with an external return pump set up. How likely is it that the problem is coming from the Mag 9.5? If that’s your thoughts, any suggestions on other reliable internal pumps that may be better? Is it a strength issue. In other words would a bigger Mag help?

 

[qwik]

I had a similar problem and it turned out to be my new skimmer. Try running without your skimmer and se if that helps. If so a foam pad between skimmer and return should help. Now that I look at your sump I would think your getting bubbles from the drain . Try a filter sock at that point to see if it is then you know where to fix. You can also put foam on the intake of your return pump.

 

[fatoldsun]

Thanks, I'll try foam on the intake. I've had the skimmer off and still saw them and I know its not in the pic but there's a filter sock on the drain

 

[shipwrecked]

+2 on foam of the return pump.I had the same prob with my mag 24 and the foam block worked like a champ.I just make sure to clean it weekly

 

[fatoldsun]

What did you guys use as a foam pad?

 

[shipwrecked]

I used the foam block that came stock on the pump.The other plus of using that block keeps debris and I found even sand from going thru the pump and back into the tank

 

[qwik]

I bought a 4x4x8" foam filter padd from Will at AO . I used my dremel to hollow out about 6" down the center and slipped it on return intake .

 

[fatoldsun]

I bought a 4x4x8" foam filter padd from Will at AO . I used my dremel to hollow out about 6" down the center and slipped it on return intake .

thanks for the tip unfortunately a craiglist setup is frequently missing those extras that come with things like new MAG pumps

 

[qwik]

You can custom the filter foam to fit your pump,I don't run a mag . You basically just hollow out the size of your intake pipe . It looks like you have a 90 on the intake just switch this out with a straight pipe and your good to go.

 

[TanksNStuff]

I doubt you are getting many bubbles (if any) due to the baffle arrangement, and I don't think the "Rube Goldberg" bubble trap really matters all that much honestly. The reason I say this is because your pump intake is near the bottom of the sump, and any bubbles that happened to make it over the baffles won't be making it to the bottom to where the pump could suck them up. You would need a severe waterfall effect for this to happen, or else the suction end would need to be closer to the surface to be able to suck in bubbles.

Think about it... bubbles float; so unless they are forced down to the bottom where your intake is... they're not getting into the pump to begin with. The water line in the return pump chamber is high enough to cushion the water over the baffles on both sides.

That means it's most certainly an issue somewhere on the discharge end. By looking at your pic, the first thing I would consider being an issue is the TEE on the discharge end... the one that goes to the right to a ball valve and then connects to the TEE in your drain piping split between the fuge and skimmer chambers. I would think that since that run is on a rise from the TEE connection back to the valve, there could be air trapped in that run and possibly getting sucked in with the return flow to the DT.

Is that valve normally open or closed Dave? If it's even slightly open, then any air in there could be getting mixed in with your return flow.

I'd start checking there and eliminate that as a possible issue before looking elsewhere.

 

[fatoldsun]

I doubt you are getting many bubbles (if any) due to the baffle arrangement, and I don't think the "Rube Goldberg" bubble trap really matters all that much honestly. The reason I say this is because your pump intake is near the bottom of the sump, and any bubbles that happened to make it over the baffles won't be making it to the bottom to where the pump could suck them up. You would need a severe waterfall effect for this to happen, or else the suction end would need to be closer to the surface to be able to suck in bubbles.

Think about it... bubbles float; so unless they are forced down to the bottom where your intake is... they're not getting into the pump to begin with. The water line in the return pump chamber is high enough to cushion the water over the baffles on both sides.

That means it's most certainly an issue somewhere on the discharge end. By looking at your pic, the first thing I would consider being an issue is the TEE on the discharge end... the one that goes to the right to a ball valve and then connects to the TEE in your drain piping split between the fuge and skimmer chambers. I would think that since that run is on a rise from the TEE connection back to the valve, there could be air trapped in that run and possibly getting sucked in with the return flow to the DT.

Is that valve normally open or closed Dave? If it's even slightly open, then any air in there could be getting mixed in with your return flow.

I'd start checking there and eliminate that as a possible issue before looking elsewhere.

hey George - thanks for weighing in

in terms of the severe waterfall - could be that water leaving my refugium is causing some issue. It just worked out that the intake is closer to that side of my return section and I didn't to baffles on that side - I gess either way the water still travels over the side and down - baffles or not. I guess my thought was the bubble trap was for anything coming from the drain(s) or the skimmer hence the trap for the skimmer section and just the "rube" trap in the fuge.

as for the tee you described - that was sort of an experiment that I don't use. It was suggested when I was doing my build that I may not want to restrict the output flow from the Mag 9.5 to extend the useful life. To deal with too much flow, I should divert some back to the fuge and leave the return line full-open. Well in hindsight I guess I should have run it back to the skimmer because if I did this it was inundating my fuge (and the rube trap) with too much flow. So, long story short, that stays closed. I don’t want to tear it all apart to re-plumb it without that so I was hoping closed would work – I would guess there’s some turbulence in the return flow because of the interruption to the path but I was hoping keeping it closed would resolve that. Maybe I need to open it each time I do a WC or any maintenance that require shutting down the return pump and let it fill with water before I close it – maybe right before the valve there’s some trapped air stirred up by the turbulence but like I said, it’s kept closed and has been.

Any other thoughts? Maybe I should just plumb the intake differently so it’s not as close to the fuge waterfall?

 

[JRWOHLER]

I tend to agree you shouldn't have bubbles. Try putting some foam around the intake. Try turning off the skimmer for a bit to see if that is it. Finnally probably it is what George is saying and you have a tiny leak in the return somewhere pulling the air in.
If you can set a return pump up with a flexible hose you can see if it is in your return lines.

 

[radiata]

Another Source of Micro Bubbles

Micro Bubbles are frequently caused by poor plumbing practices when joining PVC pipe with PVC fittings. A bad glue job can not only result in a water leak - it can also result in air being sucked into the assembly via the venturi effect. The bubbles will be small and will be ongoing. Similar results can no doubt occur with the improper use of hose clamps and not using teflon tape properly for threaded connections.

 

[JerzyFF61]

Micro Bubbles are frequently caused by poor plumbing practices when joining PVC pipe with PVC fittings. A bad glue job can not only result in a water leak - it can also result in air being sucked into the assembly via the venturi effect. The bubbles will be small and will be ongoing. Similar results can no doubt occur with the improper use of hose clamps and not using teflon tape properly for threaded connections.

i second this! many problems with micro bubbles are the result of "over thought out" plumbing. yes you did a very nice job setting up the drains and all, but i dont see the need for it to be that complicated. a big problem with that type of plumbing job is that when your overflow drains down, it carries small bubbles with it, which like said above get caught in the tees/elbows/etc. and every once and a while they release down into the sump, and can be pulled all the way down into the pump.

try the foam baffle to see if that helps. also another thing i noticed, which could be a major cause of the bubbles is where your return pump is sitting. try and relocate the pump so that it sits in the middle of its section. the water falling over the baffle can be carrying some air which in tun is getting sucked directly into the pump.

 

[JRWOHLER]

Micro Bubbles are frequently caused by poor plumbing practices when joining PVC pipe with PVC fittings. A bad glue job can not only result in a water leak - it can also result in air being sucked into the assembly via the venturi effect. The bubbles will be small and will be ongoing. Similar results can no doubt occur with the improper use of hose clamps and not using teflon tape properly for threaded connections.

That was what I said just a lot clearer.

 

[fatoldsun]

That was what I said just a lot clearer.

So can I put some gum on it to keep the air from coming in?

I don't think I can move the pump body without adding more 90s but I can extend the intake away from that side. Land yes I got too fancy with the return design but it seemed good in theory. Hindsight is 20/20. I wouldn't do it again but I'm not sure it bothers me enough to redo the drains b/c I'd have to drain the sump and which means breaking down the fuge. I'll try some other stuff that's been suggested but I'm guessing the plumbing is the most likely culprit. Thanks as always for the ideas!!

 

[JerzyFF61]

sorry jr

instead of making more 90's (which we both stated could be your problem) go buy some smooth lined tubing and replace the crazy plumbing. this will also enable you to move your pump.

so when your drain comes down, you can go from pvc to tubing. add a T -Y and split the tubing between the fuge and the skimmer section, and add a ball valve at the bottom of each tubing for flow control. i know it sucks doing it all over, but it probably will work. i had to redo my pvc setup when i first setup my tank...

 

[fatoldsun]

sorry jr

instead of making more 90's (which we both stated could be your problem) go buy some smooth lined tubing and replace the crazy plumbing. this will also enable you to move your pump.

so when your drain comes down, you can go from pvc to tubing. add a T -Y and split the tubing between the fuge and the skimmer section, and add a ball valve at the bottom of each tubing for flow control. i know it sucks doing it all over, but it probably will work. i had to redo my pvc setup when i first setup my tank...

when you say smooth lined tubing, are you talking about hose? If it’s flexible (i.e., hose) how do you get the leverage to close off the ball valves when you’re doing maintenance? And how do you keep things “in-place”? Maybe I’m too OCD for hoses that could move around. I’m not sure I see why the drains would matter? Isn’t that what the bubble-traps are for? And the skimmer with do more than the drain will anyway. I get that I should re-do the return to eliminate that “spill off” tee but I could do that far more easily that scraping all the way up to the bulkheads. As it is now, there are actually no real 90s on the return (well the spill off, but the actual run up is done with 45s. I also had a problem (right after I made all my SW and filled the tank) where I was messing with moving the sump and I knocked into a bulkhead and sprung a leak. Admittedly I panicked and that in turn caused most of the damage but I’m a bit uncomfortable (translates to a cat nickname) when it comes to messing with that. Anyway, I will have to have a good reason to change anything that will affect the bulkheads...

 

[JRWOHLER]

Flexible hose works, I have a ball valve no problems.
But that said why not just get some flexible PVC and clean up that return with one shot up to the bulkhead? Simple is better right.

 

[redfishbluefish]

I’m also running a MAG 9.5 as a return and a sump setup that is very very similar to yours. I have no issues with bubbles.


I agree with some that has already been said….especially about air being drawn in due to venturi effect. Make sure your unions have the O-ring in place. If not, that’s another source of air.

The other thought is possible cavitation at the pump. What’s up with what appears to be a 90 elbow on the intake of the pump. That could possibly cause cavitation (grasping at straws). Try taking that elbow off and see what that does.