Help me with my microbubbles

[purplegorilla]

Here is a brief history on my set up. This is a brand new tank (180). I used some of the water from another tank that I have to help it cycle faster.

At first, I thought I was having problems with the microbubbles from the return pump. So I tried to eliminate all the possible leaks, raise the water level in my refugium to preven bubbles getting suck into the return pump, reduce all possible turbulences.

After all of that, I looked closer and realized the bubbles aren't really coming out from the return nozzles. It is actually just floating around my tank. I did some searching and the only thing I can think of, are nitrogen bubbles. I do have some larger air bubbles on the side of the glass and etc..But these micro bubbles are just floating around.

The tank has diatom growing on the back.

 

[cameron]

New tanks often have this problem for a few days. It is likely the bubbles will go away on their own. Also the powerheads are likely sucking them in and chopping them up into even finer bubbles. If this is the case, you can shut down your power heads for 30 minutes or so and wipe the glass clean which should help dispurse them faster.

 

[FutureInterest]

Most likely, they are not nitrogen bubbles. Nitrogen gas is typically released from anaerobic areas in large bubbles as the small bubbles typically build up until they are then of sufficient size to escape the anaerobic area they are encased in. Since you're getting diatom growth I'm going to assume your tank has been running long enough for the bubbles associated with new tank water to dissipate.

What you're probably seeing are just micro bubbles from your return line or other flow device that are just being circulated throughout your tank. It's not that easy to see them enter the tank from the return after all they are small in size or rather "micro" in size.

Micro bubbles are caused by a myriad of different things. One of them would be a leak in the return line, which you seem to have remedied. Another is bubbles reaching the return pump which then chops them up into micro bubbles. I don't see how raising the water level remedies this, but I don't know much about your system... most commonly people use baffles to eliminate this issue.

Finally, the most common cause of micro bubbles is cavitation. This is where a low pressure area in your return line allows rapid decompression of gasses in the water. There's no easy fix for cavitation as its more of a system design flaw... Again I don't have sufficient information to pinpoint your problem and it might very well be something altogether different... Hopefully though this will point you in the right direction.

G'luck

 

[purplegorilla]

Forgot to say that my tank has been cycling for approximately 3 1/2 weeks. I added about 40lbs of live rocks in the refugium.

There is a baffle to trap the bubbles prior to the return line. I had the water level in that section only half way.

I thought cavitation are samething as turbulences..That i tried to minimized by using tubings and less 90. I looked at the return nozzle and there are no ubbles coming out from there at all. So that is what confuses me the most.

By the way cameron, I don't have any power heads in the system yet.

 

[cameron]

hmmm... air is getting in somewhere. It probably is a tiny hole or failed seal on the return somewhere. Good news is that if it is a tiny hole in the return somewhere, salt/calcium build up will likely close it off soon enough. If you used locline, you could pull the nozzles up and out of the water which can help reduce microbubbles as well. If it cavitating, you will likely hear it in the return lines. You can also temporarily tie a filter sock around the return output and see if that lessons the microbubbles in the tank.

Are you running a closed loop?

 

[wbholwell]

I have a similar problem on an established tank. The cause is either a leak in the return line or cavitation. The anti-siphon hole couldn't cause this, could it? Can anyone suggest a good method for locating a leak?

BTW, good luck, Gorilla.

 

[cameron]

Where did you drill the anti-siphon hole and is water coming out of it?

 

[purplegorilla]

I will be running close loops. Was waiting for the LFS to stock on the Koralia pumps. I am still trying to decipher what FutureInterest is trying to explain about low pressure in the return line...

The pump is Gen X 150 with approximately 12 foot rise and 11 foot horizontal throught a 1 inch tubing and reducing to 3/4 inside the tank since I didnt' have enough room. I know that the pump is more than sufficient to push that volume.

 

[wbholwell]

Here's a diagram of my return. The arrow from the anti-siphon hole also shows the direction of flow. I'm thinking the location of the hole relative to the 90 deg bend might be causing the problem (it's very close to the bend).

BTW, I bought this as a complete setup- this is the way it came.
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<legend> Attached files </legend>

 

[cameron]

purpleGORILLA;56216 wrote: I will be running close loops. Was waiting for the LFS to stock on the Koralia pumps. I am still trying to decipher what FutureInterest is trying to explain about low pressure in the return line...

The pump is Gen X 150 with approximately 12 foot rise and 11 foot horizontal throught a 1 inch tubing and reducing to 3/4 inside the tank since I didnt' have enough room. I know that the pump is more than sufficient to push that volume.

Return pipes that are too large compared to the intake and/or the pumps ability to push can cavitate since it cannot create pressure in the return so it can't purge out all the air. Doesn't sound like this is the problem, but that is one long run. What does the piping consist of?

Here's a diagram of my return. The arrow from the anti-siphon hole also shows the direction of flow. I'm thinking the location of the hole relative to the 90 deg bend might be causing the problem (it's very close to the bend).

Is the hole above or below the water line?

 

[wbholwell]

Cameron;56222 wrote:
Is the hole above or below the water line?

It's actually in the overflow, well above the waterline. The water coming out hits the back wall of the overflow.

 

[wbholwell]

purpleGORILLA;56216 wrote:
The pump is Gen X 150 with approximately 12 foot rise and 11 foot horizontal throught a 1 inch tubing and reducing to 3/4 inside the tank since I didnt' have enough room. I know that the pump is more than sufficient to push that volume.

What is the inlet condition on your GenX? (i.e. are there any bends in the pipe before the pump, is the pump located above the waterline of your sump, any valves, etc.)

 

[ouling]

It is not your pipes because it only leak water, it don't suck air in since the PVC is of much greater pressure than 1 ATM.

It is something chopping the bubble. Make sure your return pump and your overflow drain hose isn't too close, usually the overflow hose will dump water in and introduce massive amounts of air, if any of this is sucked in by a return pump then you'll see microbubbles. If it bubbles are very fine and you're sure it's not sand, then you can bet your clown fish that it's chopped by a prop pump.

 

[FutureInterest]

PurpleGorilla -

Cavitation is not caused merely by return line piping that is too large. That would of course cause major cavitation, but that is not what we appear to be seeing here. Instead it appears that there is probably one spot maybe two in a return line that long where a low pressure area exists that is allowing cavitation to occur. For example, if you have ball valve somewhere after the return line you can easily get cavitation from the low pressure area after the ball valve. It could also occur after an elbow or even after a coupling. Anywhere that the size of the aperature decreases and then opens up again is a possible site of cavitation. I apologize if I'm not being clear, feel free to PM me with any questions .

Byran -

I doubt that the anti-siphon hole in conjunction with the 90 degree bend there would cause enough of a low pressure area for cavitation. It's probably occuring somewhere else in the return line. As for leaks, that's easy to check for... just look for the telltale salt creep at the PVC joints. To remedy a leak you can use silicone on the exterior of the joints. As for testing to see if that anti-siphon hole is the culprit, simply seal it temporarily with some epoxy or a dab of superglue. If the symptoms persist then you'll know its due to some other portion of the return line.

G'luck

 

[wbholwell]

Thanks, Jin! I'll take your advice and let you know how it turns out.

 

[cameron]

I bet the anti-syphon hole being above the water line is drawing air in similar to a venturi. The speed of the water passing by can cause air to be drawn into the pipe.

 

[wbholwell]

Cameron;56312 wrote: I bet the anti-syphon hole being above the water line is drawing air in similar to a venturi. The speed of the water passing by can cause air to be drawn into the pipe.

That's what I was worried about. I guess I'll try to plug it temporarily, and see if that fixes the problem.

Thanks

 

[circlek]

Can LocLine cause microbubbles? I also have issues with microbubbles, and I also use LocLine at the output of the return. Just by the feel of the locline it seems that air might be able to get in there. Maybe mine is worn out?

 

[purplegorilla]

Well after looking more carefully with a metal halide hooked up at the refugium, I am thinking there are still some bubbles that aren't trapped in the baffles prior to getting suck into the return pump. So I am gonna try the sock to see.

 

[mitchelliii]

Used to have this problem with venturi effect. If it is, you should be able to hear it (like a drain). I tinkered with a durso that I made so I could twist it to get the right amount of air. Also, consider a big sponge filter like you get with Mag pumps over the intake. It won't slow down flow, and it lets bubbles have a chance to trickle out before going back up. I thought it would just make smaller/more bubbles but it has worked for me. Also, even more extreme is to use the poly/cotton like mesh before the return. Looks like stuffing for stuffed animals. Only con is that it will prevent pods and collect a lot more detritus and require some attention? Have you tried not operating skimmer to see if that is part of the cause? Last - when mine was cycling I had a lot of algae and I think it actually made a lot of bubbles. It was a lot of algae~!