Strange case of the reappearing micro bubbles

[Aquarist007]

I have been experiencing a problem with micro bubbles that seem to go away after I have tightened or tinkered with the fittings on the return line but only reappear again after a couple of weeks.
I am postive it is sucking in air somewhere and is not due to the drainage or the protein skimmer in the sump.
After I have retaped and tighten all fittings to as far as I can go I have now siliconed everyone of them but this time the bubbles continue.
The only other spot I can see where air could be sucked in would be the loc lines since where they come over the internal overflow they are actually out of the water column. The last two times I have moved them or bumped them when cleaning I have had micro bubbles reappear. I have followed the line downstairs and tightend the fittings on the line between the loc lines and the return pump. This has stopped the bubbles but not this time.
In the past I have tightened the side from sump to pump and it has stopped the bubbles temporarily---so it just doesn't figure

and leads me back to the question if it could be the loc lines themselves??

sump to pump side:

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0379.jpg

pump to dt side(foreground)

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0055.jpg

[Aquarist007]

this is a first---I have to bump my own thread??

[nebraskareef]

This may not be your problem, but I feel like the plumbing on that pump might be too small on the intake side. I know that can cause cativation, which would result in micros...

You would think if that was the case, it would happen all the time, but as you know, pumps can vary in the speed at which the motor turns.

I don't know, probably not the problem, but an idea.

You could temporarily rig up a return that doesn't use the locline to see if you can try to isolate it further.

[Bill14]

To test the loc line theory, can you temporarily replace the loc line with some PVC fittings? If the bubbles go away, then it was the loc line. If they don't, then it's not.

EDIT: I guess I should have read the previous post, but now that two people have suggested it, give it a shot. :D

[BeanAnimal]

As mentioned..

1) Pump intkae restriction could be causing cavitation. To test this restrict the output somewhat and see of it resolved the issue.

2) Locling is not watertight... it could be introducing air. However, if the locline is at the output, it is unlikely that there is enough velocity to pull air in.

[Aquarist007]

<a href=showthread.php?s=&postid=14956075#post14956075 target=_blank>Originally posted</a> by BeanAnimal
As mentioned..

1) Pump intkae restriction could be causing cavitation. To test this restrict the output somewhat and see of it resolved the issue.

2) Locling is not watertight... it could be introducing air. However, if the locline is at the output, it is unlikely that there is enough velocity to pull air in.

thanks for the support guys.
It is very easy to turn down the output flow with a turn of the ball valve so I will try that

RE Loc lines
I have drilled a 1/8 hole under the main body of the loc lines close to the surface as a safety feature should there be a power failure
But that hold has been there for years.
I am beginning to think it is the pump because:

RE pump
About 4 months ago the pump swallowed the business end of one of those cheap digital thermometers. Since the pump did not seem affected I did not take it off line and take it apart. Is it possible for the plastic bulb of that thermometer which is either still in there or has chipped off a blade of the impeller, to be causing intermittent cavitation.
If so I won't hesitate in taking the pump off line and checking out the impeller---I just hate to take that pump apart if it is not the problem

[melev]

Two things:

Check the strainer that you have inside the sump, the one that leads to the return pump. If that is clogged up, the pump can create bubbles.

The anti-siphon hole in the locline should be submerged fully, 1/2" beneath the water's surface. You said it was very close to the surface, but not whether it was submerged or not.

[Aquarist007]

<a href=showthread.php?s=&postid=14957676#post14957676 target=_blank>Originally posted</a> by melev
Two things:

Check the strainer that you have inside the sump, the one that leads to the return pump. If that is clogged up, the pump can create bubbles.

The anti-siphon hole in the locline should be submerged fully, 1/2" beneath the water's surface. You said it was very close to the surface, but not whether it was submerged or not.

thanks for your input Marc

I don't have a strainer on the inside of the sump but I can easily undue the line from the slip joint and run a cleaner brush through it.

The position of my loc lines as they come over the overflow strainer does not allow them to be fully submerged in 1/2 inch of water.

How do you feel about the pump--should I be taking it apart to see if that thermometer head and 6 inches of wire is still in the impeller? could that have the same effect as a plugged strainer

What has me baffled is that over the last few months I the micro bubbles were inconsistent--and when they appeared it was usually after a water change in the sump and or altering the position of the loc lines to direct the flow away from some corals.
I would then methodically tighten all the fittings along the return lines and it would go away. This time it hasn't gone away and it is really intense---the whole tank this time is full of micro bubbles.

Right now I will go and check the return line to see if it is plugged and report back later.

[melev]

It doesn't hurt to open up the pump and check it for damage.

Anti-siphon holes should always been submerged. It sounds like yours are not. Can we see a picture of that spot?

[Aquarist007]

<a href=showthread.php?s=&postid=14957767#post14957767 target=_blank>Originally posted</a> by melev
It doesn't hurt to open up the pump and check it for damage.

Anti-siphon holes should always been submerged. It sounds like yours are not. Can we see a picture of that spot?

Okay I checked the return from the sump with a home made router and there were no obstructions

Here is a couple of pictures of the loc lines and micron bubbles

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0609.jpg

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0610.jpg

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0611.jpg

sorry I can't any from the top down---I can't lift the oak canopy off by myself

[melev]

So where is the anti siphon hole? Inside the overflow?

What did the return pump's impellar look like?

Is the return section bubble free?

[Aquarist007]

<a href=showthread.php?s=&postid=14958157#post14958157 target=_blank>Originally posted</a> by melev
So where is the anti siphon hole? Inside the overflow?

What did the return pump's impellar look like?

Is the return section bubble free?

underneath about here

http://i142.photobucket.com/albums/r107/reefescapetangster/loclinesarrow.jpg

[2frosty4u]

If I were you I would take a trip to mops and see Dan for a few plumbing parts. First I would get a new 1" bulkhead (slip-slip) to replace the one in the sump now. Then get a new 1" valve (you may already have this one) also slip-slip conections and finally a 1" union slip-slip. Replace half of the threaded union with half of the slip one and redo the connection from the pump to the sump with glued and not screwed connections. When you're sump sprung a leak and we had to do that quicky fix we worked with the parts at hand and those parts are most likely the cause of the bubble trouble. The way it is now everyone of those threaded joints are a possible source for air to be sucked into the system under negative pressure. You run a Blueline 100HD pressure rated pump that could suck a golf ball through a garden hose so its not hard to see it suck air through the threads.

[Aquarist007]

<a href=showthread.php?s=&postid=14958611#post14958611 target=_blank>Originally posted</a> by 2frosty4u
If I were you I would take a trip to mops and see Dan for a few plumbing parts. First I would get a new 1" bulkhead (slip-slip) to replace the one in the sump now. Then get a new 1" valve (you may already have this one) also slip-slip conections and finally a 1" union slip-slip. Replace half of the threaded union with half of the slip one and redo the connection from the pump to the sump with glued and not screwed connections. When you're sump sprung a leak and we had to do that quicky fix we worked with the parts at hand and those parts are most likely the cause of the bubble trouble. The way it is now everyone of those threaded joints are a possible source for air to be sucked into the system under negative pressure. You run a Blueline 100HD pressure rated pump that could suck a golf ball through a garden hose so its not hard to see it suck air through the threads.

will do---let me know if you are up to a visit and I will bring you down that gsp

[Aquarist007]

some will find this very interesting--others dumb that I didn't do something about this a long time ago. These blue line pumps are simply amazing---I don't think I would do so well with this caught in my throat :)

thats no wopping big copepod--its the sensor end plus plastic suction cup and about 6 inches of plastic line from the thermometer that the pump ate about 6 months ago

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0612.jpg

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0613.jpg

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0614.jpg

[nebraskareef]

Well there is your problem!

Glad you found it, lets hope it takes care of the micros!

[Aquarist007]

I took my buddy 2frosty4u's advice and replaced the rest of the line with pvc slip joints instead of threaded

http://i142.photobucket.com/albums/r107/reefescapetangster/DSC_0615.jpg

so I don't know if it was pump cavitation or the fittings or both because I wasn't about to put 35 gals of water back and forth in the sump
At any rate the system got 35 gals of fresh salt water and there are no microbubbles yeah

[sjm817]

LOL. Too funny! Glad to see you got it fixed. Hopefully, the MB are gone for good.

[Aquarist007]

<a href=showthread.php?s=&postid=14970068#post14970068 target=_blank>Originally posted</a> by sjm817
LOL. Too funny! Glad to see you got it fixed. Hopefully, the MB are gone for good.

I sure they will be Scott---that piece of thermometer was sitting in there where the plastic suction cup was definetly interfering with the flow--now doubt now there was cavitation.

[2frosty4u]

Glad to hear that you got things figured out and found the thermometer junk. Fingers crossed that the bubbles are gone for good.

[Aquarist007]

<a href=showthread.php?s=&postid=14971259#post14971259 target=_blank>Originally posted</a> by 2frosty4u
Glad to hear that you got things figured out and found the thermometer junk. Fingers crossed that the bubbles are gone for good.

yes I am glad ---now I won't feel bad having to ask you for help;)

another funny thing I forgot about. Remember that bipass we installed for the extra pump pressure. I had shut it off about 5 months ago because I felt I didn't need it. I had noticed a decrease in the blueline at that time.
Well I went upstairs after putting the pump back on line and I had like 1/2 a centimeter left before the display tank overflowed :eek2: :lol:
I'd have been a dead damsel if I had ruined that carpet in that room
You are a brilliant plumber my friend with the foresight to install that bipass:smokin:

[Aquarist007]

In the last week my system has received over a 55gal water change. What a difference to the clarity of the water.
I highly recommend that be done every few months or so--it seems to make alot of difference compared to my biweekly water changes

[ari5736]

I have situation with my Blueline 70. When I put a screen on the input of the pump by the sump I get lots of bubbles (I think cavitation), but without a screen I am looking at a similiar situation with my pump from whatever may get sucked through there.
I am going to have to try and use a larger screen I guess.

[nebraskareef]

<a href=showthread.php?s=&postid=14974515#post14974515 target=_blank>Originally posted</a> by ari5736
I have situation with my Blueline 70. When I put a screen on the input of the pump by the sump I get lots of bubbles (I think cavitation), but without a screen I am looking at a similiar situation with my pump from whatever may get sucked through there.
I am going to have to try and use a larger screen I guess.

more surface area = more unrestricted suction = less cavitation.

I think the larger screen will solve your problem.

[Aquarist007]

<a href=showthread.php?s=&postid=14974515#post14974515 target=_blank>Originally posted</a> by ari5736
I have situation with my Blueline 70. When I put a screen on the input of the pump by the sump I get lots of bubbles (I think cavitation), but without a screen I am looking at a similiar situation with my pump from whatever may get sucked through there.
I am going to have to try and use a larger screen I guess.

other then the thermometer that I dropped into the sump by accident there is really not too much in there that would not be sucked right through the blueline.

[melev]

Glad you got it fixed. What type of cement did you use for the PVC fittings? I've not seen that color before.

[Aquarist007]

<a href=showthread.php?s=&postid=14981412#post14981412 target=_blank>Originally posted</a> by melev
Glad you got it fixed. What type of cement did you use for the PVC fittings? I've not seen that color before.

cement---I was suppose to use cement:confused:

Schwartz D1 medium bodied grey PVC40 (Roma Hardware)

the store just happened to me on the way to my aquarium hardware supplier;)

Thanks for checking back with me on how I did.

[melev]

As long as it is good for PVC, that's all that matters. :)

[Aquarist007]

<a href=showthread.php?s=&postid=14981477#post14981477 target=_blank>Originally posted</a> by melev
As long as it is good for PVC, that's all that matters. :)

It hasn't come apart yet;)

While I have your attention---I noticed from reading material on your web site that you dose quite regularily with phyto. If you do this there is obviously an excellent reason for doing so.
I was under the impression that phyto was good for copopods ect and zooplankton was good for the corals?

[melev]

I got away from dosing Phyto a long time ago. I was doing it for pod growth primarily, although some corals have been dissected to find phyto cells in their digestive tracts. The trick is to provide the right kind of plankton that they can devour. Nano tends to have a hard shell that some stuff can't break down, not unlike what happens when we eat corn. :lol:

It probably wouldn't hurt my system to dose it, but all the food I put in the tank becomes drizzle from my fish when they expel waste, so I've not seen the need like I did years ago.

[Aquarist007]

<a href=showthread.php?s=&postid=14981566#post14981566 target=_blank>Originally posted</a> by melev
I got away from dosing Phyto a long time ago. I was doing it for pod growth primarily, although some corals have been dissected to find phyto cells in their digestive tracts. The trick is to provide the right kind of plankton that they can devour. Nano tends to have a hard shell that some stuff can't break down, not unlike what happens when we eat corn. :lol:

It probably wouldn't hurt my system to dose it, but all the food I put in the tank becomes drizzle from my fish when they expel waste, so I've not seen the need like I did years ago.

great glad you took the time to explain that. I still dose phyto to the two refuges but use a mixture of oyster eggs and cylopeeze for the corals.