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DarkFORCE
02/25/2008, 11:13 AM
I am having a big problem with microbubbles from the return pump. The pump is a new Gen-X PCX55HP. It has a 1" intake and outlet. The red line in the pictures is the output and the blue is the intake. In the second picture are the returns in the tank which are 2 DIY Penductors. I have removed the penductors to see if that is the cause and the bubbles are the same. I am really not sure what the cause is. It has been 4 days now and they have not settled at all.

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=Return1.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/Return1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=Return2.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/Return2.jpg" border="0" alt="Photobucket"></a>

sjames
02/25/2008, 11:22 AM
could be sucking air from a leak in your inlet plumbing.

DarkFORCE
02/25/2008, 11:33 AM
<a href=showthread.php?s=&postid=11936700#post11936700 target=_blank>Originally posted</a> by sjames
could be sucking air from a leak in your inlet plumbing.

If that was the case wouldn't leak when the pump is off? I was thinking that could be the case also.

sjames
02/25/2008, 12:12 PM
sure, but it could take a long time for it to show up. But that seems like the most likly answer.

how much flow is that pump rated for? Running a elbow right at the inlet is a bad idea also, you may want to up your pipe diameter to support the elbow.

DarkFORCE
02/25/2008, 12:15 PM
<a href=showthread.php?s=&postid=11937096#post11937096 target=_blank>Originally posted</a> by sjames
sure, but it could take a long time for it to show up. But that seems like the most likly answer.

how much flow is that pump rated for? Running a elbow right at the inlet is a bad idea also, you may want to up your pipe diameter to support the elbow.

It is a pressure rated pump at 1200gph.

sjames
02/25/2008, 12:17 PM
it would definatly be in your best interests to put 1.5" pipe from the sump to the pump then, with the 1" elbow its possible your getting cavitatin, although I think you would hear excess noise. Either way, the 1" pipe with elbow will shorten the life of your pump.

sirreal63
02/25/2008, 12:22 PM
It could be cavatation from the reduced inlet size or possible micro bubbles flowing from the drain through the system. That is a lot of water movement through the sump. What size is the piping from the sump to the pump? The ball valve can also be a restriction, if you restrict the pump you will cavatate. 2" pipe may be required. Check the sump before the pump feed to see if there are micro bubbles there, if there are you are flowing too much through the sump...the bubbles never get a chance to dissipate and get circulated back through the display.

DarkFORCE
02/25/2008, 12:39 PM
The pump has 1" inlet and outlet. I am using 1" pipe on both sides. I did not reduce the pipe at all. I do not see any bubbles in the sump that the pump might be pushing back.

sjames
02/25/2008, 12:49 PM
kill two birds with one stone, replace the section of pipe between the sump and pump with 1.5", if its a leak, that should fix it, if its cavitation that will also get fixed.

DarkFORCE
02/25/2008, 12:59 PM
<a href=showthread.php?s=&postid=11937366#post11937366 target=_blank>Originally posted</a> by sjames
kill two birds with one stone, replace the section of pipe between the sump and pump with 1.5", if its a leak, that should fix it, if its cavitation that will also get fixed.

So run 1 1/2" from sump to the pump. Then at the pump reduce it to 1"?

sjames
02/25/2008, 01:03 PM
yessir

DavinD
02/25/2008, 01:40 PM
Can you show a shot of your full sump? Is it possible you don't have a bubble trap between the drain side and the return side?

kgouso
02/25/2008, 01:42 PM
This is totally a guess, but I would think that it has something to do with the tee going to your returns.

Notice that you have much more bubbles in the right return?

My logic tells me that water will follow the least resistance. that being straight up to the left return.

can you turn off the right return only and see if the bubbles go away?

or can you restrict the left to force a complete flow to the right return.

DarkFORCE
02/25/2008, 01:59 PM
<a href=showthread.php?s=&postid=11937804#post11937804 target=_blank>Originally posted</a> by DavinD
Can you show a shot of your full sump? Is it possible you don't have a bubble trap between the drain side and the return side?

I am going out to lunch with my inlaws. I will post a pic when I get home.

sirreal63
02/25/2008, 02:04 PM
Microbubbles will flow through most bubble traps but he already stated that he had no microbubbles before the pump, only after which is a sign of cavatation, a strong pump being starved for water. :-)

DarkFORCE
02/25/2008, 02:51 PM
I will try to change the intake to 1 1/2" I think and see what that does. Can not hurt anything.

DavinD
02/25/2008, 03:24 PM
I don't disagree that cavatation could be the issue, I just like to look for simpler answers first. I do not see that he has specifically said that there are no micro bubbles in the sump to begin with, just that the pump was not spitting them out on the intake side.

That being said, I went back and looked at his build thread in our club forum and came across this shot.

http://i249.photobucket.com/albums/gg209/rmilyard/IMG_0756.jpg

It seems to me that in this picture the water level in the sump is too high making his bubble trap useless. The water level may be lower now.

sirreal63
02/25/2008, 03:47 PM
There may be other issues at play, however, 1" plumbing is too small to feed that pump and is the logical place to start.

rexdenton
02/25/2008, 04:13 PM
If not an air induction (leak) in the intake side, check your location of the 1st 90 degree elbow on your plumbing; it should be at least 10x the pipe diameter from the inlet, or the water that turns the corner will begin cavitating/cause micro bubbles.

Passing this tid-bit along...Got greedy with avaialble space,Tried to plumb my new Iwaki knowing AND disregarding this information....voila, beautiful micro bubbles!!! (more wet towels and the aroma of pvc solvent in my future).
R

SHARKBAITNC
02/25/2008, 04:21 PM
My guess is the plumbing to small that feeds the pump. I had the same problem with a little giant 4md and a ball valve, look in the ball valve it is smaller than 1" go with a bigger size like what eveyone else is saying, and I bet that will fix it. It did for me

Nick

DarkFORCE
02/25/2008, 04:23 PM
Here are some pictures. Taken with my iPhone so bare with quality.

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=IMG_0006.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/IMG_0006.jpg" border="0" alt="Photobucket"></a>

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=IMG_0007.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/IMG_0007.jpg" border="0" alt="Photobucket"></a>

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=IMG_0009.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/IMG_0009.jpg" border="0" alt="Photobucket"></a>

<a href="http://s249.photobucket.com/albums/gg209/rmilyard/?action=view&current=IMG_0010.jpg" target="_blank"><img src="http://i249.photobucket.com/albums/gg209/rmilyard/IMG_0010.jpg" border="0" alt="Photobucket"></a>

DavinD
02/25/2008, 04:56 PM
OK, I capitulate. Definately not coming from your return. Sorry if I took you off track.

kgouso
02/25/2008, 05:01 PM
Did you try and turn off the right side return to see if the bubbles stop?

DarkFORCE
02/25/2008, 05:02 PM
<a href=showthread.php?s=&postid=11939731#post11939731 target=_blank>Originally posted</a> by kgouso
Did you try and turn off the right side return to see if the bubbles stop?

I did not install ball valves on the right and left side. I should have but space issues.

sjm817
02/25/2008, 05:08 PM
I cant tell from those pics if there are mb in the sump or not. The glass is pretty hard to see through. If you clean the glass up, and shine a bright spot light through the side of the sump, do you see mb?

kgouso
02/25/2008, 06:08 PM
<a href=showthread.php?s=&postid=11939749#post11939749 target=_blank>Originally posted</a> by DarkFORCE
I did not install ball valves on the right and left side. I should have but space issues.


I would cap the right side in the DT to test and rule that out as a possibility.


I really get the feeling it has somthing to do with that T after the pump (because you are getting so many more bubbles on that side according to the picture)

If it were before the pump it would be an even split of bubbles...or perhaps more on the left because that is the straight shot for the water.

As a quick test, I would cap the right return outlet and see if it gets rid of your bubbles...(you are obviously going to get much more power out of your other return so you may need to adjust the flow direction of the other outlet and or valve it back so you don't blow your sand bed away.


On the other end...It seems like a quick test of if that elbow is causing the inlet to not keep up with the pump is to valve the return valve back and slow down your gph.