Help with surface slime.

[bower23]

I finally got my system all set up but now I have surface slime. If I look through the tank at the top, I can see slim build up. This can't be good. Info- 72g with 600g overflow into a sump with skimmer and return pump. The return is fed through pvc pipes that go over the back, down into the sand bed, then they branch off into the corners, with spray nozzles popping up through the sand. The problem is the overflow isn't getting all the slim off the top. So, it's just building up on the one side. I know I can put a powerhead close to the surface to stir things up but I want that stuff gone. Not just mixed up. Is there a small filter that skims from the top instead of pulling from a collection pipe? I was thinking something like a Whisper 40I internal filter but with reverse water flow. Am I making any sense??

 

[reefkeeper135]

sounds like you need to adjust the skimmer, what kind are you running?

 

[bower23]

I bought it off ebay, so it's not a name brand. It's huge and skims very well.... not a cheapy... just not a name brand. But it looks like the overflow really isn't pulling all that stuff down to the sump. Just what is right in front of it.

 

[marino420td]

I had a similar problem with my overflow. If I turn my pump on full blast, it doesn't skim the top of the water that well with the increased flow. If I choke the pump down some using a ball valve, I get good surface skimming. Something you might try as well.

 

[bower23]

bump

 

[crash519]

You need to do something to break the surface of the water up. Point your return slightly up to casue turbulence and you should see the slime disappear.

 

[ob1thx1138]

I am having a similar problem. One thing I have noticed is that the water level in my overflow is almost the same as the level in the tank, but if I unplug my return pump the level in the overflow drops and the slime is skimmed off of the surface. Could it be that my overflow is not able to keep up with my pump, or it just barely keeps up?

 

[RhodeIslandReef]

I would adjust your ball valves on the return and the overflow so the water level in the rear is lower than tank level.

Also, not sure what else your using for flow in your tank, but if you are using powerheads, I would use those to agitate the surface of the tank to possibly push the surface water in the direction of the overflow.

 

[sjm817]

If the water level in the overflow is too high, it wont surface skim. The water level in the INSIDE of the overflow has to be below the bottom of the teeth. If it isn't you need to adjust your standpipe or you have too much flow from the return pump.

 

[ob1thx1138]

Actually I discovered that my problem was caused by algae growth in my U-tubes I cleaned them out and the surface scum skimmed right off.

 

[sjm817]

That is because the reduced flow in the U Tube causes the level in the skimmer box to rise. A nice clean U Tube flows well and the level in the skimmer box will be lower.

 

[marino420td]

<a href=showthread.php?s=&postid=7881818#post7881818 target=_blank>Originally posted</a> by sjm817
If the water level in the overflow is too high, it wont surface skim. The water level in the INSIDE of the overflow has to be below the bottom of the teeth. If it isn't you need to adjust your standpipe or you have too much flow from the return pump.

What is the ideal height of the standpipe in the outside box of a U-tube overflow?

 

[sjm817]

It depends. If there is no baffle, it has to be high enough to keep the end of the U Tube submerged. If there is a baffle, you have a little more flexibility and can make it shorter, although that can cause noise from the waterfall. No easy answer. It depends on the overflow, how much flow, etc.

 

[joeycadre]

out a hydor on one of my closed loop returns and it breaks up the surface much better now.