flim on the top

dsrich69 · 10/21/2008, 03:11 PM

Everything in the tank tests fine . But we have a film on the top of the water that we can't seem to get rid of . I have an over the back over flow and I'd think that should that the film off the top but it doesn't .

My wife has even taken a cup and scooped the top of the water and she can get it to go for a while but it comes right back the next day . Its driving her crazy so any ideas would help ME greatly LOL. Thanks in advance.

Ryan45 · 10/21/2008, 03:15 PM

Lower the water level a bit. Overflow should take care if it.

seapug · 10/21/2008, 03:17 PM

Raising or lowering the water level in a tank with an overflow is only possible by raising or lowering the overflow. That's the idea of having one.

Having a surface skimming overflow is step one (and the most important thing). Since you have that, all you should need to do is aim a powerhead so it pushes the water toward the overflow or aim your return nozzle so the surface of the water circulates the water in such a way that the surface scum gets pushed to the overflow.

Sugar Magnolia · 10/21/2008, 03:21 PM

Quote:

Originally posted by seapug
having a surface skimming overflow is step one (and the most important thing). Since you have that, all you should need to do is aim a powerhead so it pushes the water toward the overflow or aim your return nozzle so the surface of the water circulates the water in such a way that the surface scum gets pushed to the overflow.

+1

ReefEnabler · 10/21/2008, 03:22 PM

seapug, if you just point the return at the top, wouldn't you risk recycling much or the same sump water over and over, rather than pullig more water from the display? or do you think thats not an issue?

Sugar Magnolia · 10/21/2008, 03:23 PM

True, the return flow wouldn't be as optimal as a separate powerhead aimed from a different part of the tank.

ReefEnabler · 10/21/2008, 03:25 PM

I've also been thinking about switching my returns to eductors... that might mix the return flow alot more with tank water.

seapug · 10/21/2008, 03:26 PM

Perhaps I wasn't clear. I mean aiming the return so the surface of the water circulates in a large circle around the perimeter of the tank. If you do this, all the scum will eventually end up in the overflow-- almost like a big whirlpool.

ReefEnabler · 10/21/2008, 03:33 PM

thats actually how I sort of have mine right now.... the issue is that I get a *slight* film at the top thats always just a circle in the very center of the tank where the water is whirling around it. I might try the eductors or another powerhead aimed at the surface like suggested.

thanks.

Breakin newz · 10/21/2008, 04:36 PM

Can u get a picture of ur overflow setup? I bet you it is improper setup of overflow, I had the same exact problem and had to redo mine!

dsrich69 · 10/21/2008, 05:11 PM

the overflow is a two box system, one box inside the tank with slots and one outside connected to the hose to the sump, with a u-tube between them.

Breakin newz · 10/21/2008, 06:01 PM

Ah so its the non-perminent ones? If so and if you can try raising it allittle, like I said I had to mess with my height settings on mine for it to skim the surface...

dsrich69 · 10/21/2008, 07:08 PM

that just raises the tank level

NewBostonConst · 10/21/2008, 07:41 PM

I take a plastic container and push it down in the top of the water so that it flows very quickly over the edge of the container and fills the container. If you do this a couple times a day for a couple day it will be gone for good. Then just aim a large power head at the top of the water. The scum will also stick to the out side of the container so wash it off with hot water each time.

This works really good for me.

TheH · 10/21/2008, 07:46 PM

Perhaps your return pump is not powerful enough to force things to get sucked into the overflow. This happened to me once when I had to use a maxijet1200 as a return pump for a few days. The flow is just not powerful enough to disturb the thin layer on top of the water.

Breakin newz · 10/21/2008, 07:58 PM

Quote:

Originally posted by dsrich69
that just raises the tank level

Raise's the tank level? Wow that is crazy?

Or did you mean raise's the water level?!

And im not talking about a huge move up, just very little.. So there might be a slight increase in water level height in main tank but that should not be a problem...

Breakin newz · 10/21/2008, 08:00 PM

Quote:

Originally posted by TheH
Perhaps your return pump is not powerful enough to force things to get sucked into the overflow. This happened to me once when I had to use a maxijet1200 as a return pump for a few days. The flow is just not powerful enough to disturb the thin layer on top of the water.

This could be the problem also.....

Rascal1371 · 10/21/2008, 08:02 PM

This probably isn't it but just to be sure it isn't overlooked -- Make sure there is at least a 1/2" - 1" drop from the tank's water level to the water level in the overflow.

I see this happen in my tank when the water level in the overflow rises so the water level in the whole tank is above the weir of the overflow. This means the overflow is no longer skimming the surface.

Breakin newz · 10/21/2008, 08:05 PM

Quote:

Originally posted by Rascal1371
This probably isn't it but just to be sure it isn't overlooked -- Make sure there is at least a 1/2" - 1" drop from the tank's water level to the water level in the overflow.

I see this happen in my tank when the water level in the overflow rises so the water level in the whole tank is above the weir of the overflow. This means the overflow is no longer skimming the surface.

This guy is telling the truth.... This is exactly what my problem was!

wrott · 10/21/2008, 09:00 PM

You probably just need to agitate the surface more w/ a PH pointed straight up--no more film. The "filmate" will eventually be processed by your filtration.

BuddhaKiss · 10/21/2008, 09:10 PM

I agree with raising the overflow up a lil. It's possible that you're either maxing out the gph rating of the external overflow, or you're return isn't strong enough...either way, the amount of water that is entering the chamber (inside the tank) is too much for the return pump. Basically, make sure the water level of the inside the overflow box is below that of the tank...this should create better "suction" and provide adequate surface skimming IME.

10/21/2008, 03:11 PM	#1
dsrich69 Registered Member Join Date: Sep 2008 Location: Norway,Maine USA Posts: 29	flim on the top Everything in the tank tests fine . But we have a film on the top of the water that we can't seem to get rid of . I have an over the back over flow and I'd think that should that the film off the top but it doesn't . My wife has even taken a cup and scooped the top of the water and she can get it to go for a while but it comes right back the next day . Its driving her crazy so any ideas would help ME greatly LOL. Thanks in advance. __________________ 75 gal Reef, sump for 75 gal,built in skimmer, compac lights, 70+ lbs live rock, 3" crushed coral, 2 power heads,, Current Tank Info: 75 reef

10/21/2008, 03:17 PM	#3
seapug Registered Member Join Date: Dec 2006 Location: 4980 ft. Posts: 7,954 Blog Entries: 1	Raising or lowering the water level in a tank with an overflow is only possible by raising or lowering the overflow. That's the idea of having one. Having a surface skimming overflow is step one (and the most important thing). Since you have that, all you should need to do is aim a powerhead so it pushes the water toward the overflow or aim your return nozzle so the surface of the water circulates the water in such a way that the surface scum gets pushed to the overflow. __________________ insert clever saying here. Current Tank Info: 200 gallon custom Marineland DD peninsular tank. LPS dominated mixed reef. Previous 90 gallon mixed reef TOTM April 2009. Last edited by seapug; 10/21/2008 at 03:23 PM.

10/21/2008, 03:22 PM	#5
ReefEnabler Premium Member Join Date: Oct 2007 Location: Cary, NC Posts: 3,760	seapug, if you just point the return at the top, wouldn't you risk recycling much or the same sump water over and over, rather than pullig more water from the display? or do you think thats not an issue? __________________ - Ryan B "that is enough skimmate to ruin lives." - GSMguy Current Tank Info: 220g Display, 70g sump, 35g frag, 50g fuge, 2x250w MH, 1x400w MH, 2x80w T5, 2x140w VHO Actinic

10/21/2008, 03:23 PM	#6
Sugar Magnolia Registered Member Join Date: Feb 2003 Location: Northern VA Posts: 17,691	True, the return flow wouldn't be as optimal as a separate powerhead aimed from a different part of the tank. __________________ Adrienne The only thing to fear is fear itself....and spiders.

10/21/2008, 03:25 PM	#7
ReefEnabler Premium Member Join Date: Oct 2007 Location: Cary, NC Posts: 3,760	I've also been thinking about switching my returns to eductors... that might mix the return flow alot more with tank water. __________________ - Ryan B "that is enough skimmate to ruin lives." - GSMguy Current Tank Info: 220g Display, 70g sump, 35g frag, 50g fuge, 2x250w MH, 1x400w MH, 2x80w T5, 2x140w VHO Actinic

10/21/2008, 03:15 PM	#2
Ryan45 Registered Member Join Date: Aug 2007 Posts: 97	Lower the water level a bit. Overflow should take care if it.

10/21/2008, 03:26 PM	#8
seapug Registered Member Join Date: Dec 2006 Location: 4980 ft. Posts: 7,954 Blog Entries: 1	Perhaps I wasn't clear. I mean aiming the return so the surface of the water circulates in a large circle around the perimeter of the tank. If you do this, all the scum will eventually end up in the overflow-- almost like a big whirlpool. __________________ insert clever saying here. Current Tank Info: 200 gallon custom Marineland DD peninsular tank. LPS dominated mixed reef. Previous 90 gallon mixed reef TOTM April 2009.

10/21/2008, 03:33 PM	#9
ReefEnabler Premium Member Join Date: Oct 2007 Location: Cary, NC Posts: 3,760	thats actually how I sort of have mine right now.... the issue is that I get a slight film at the top thats always just a circle in the very center of the tank where the water is whirling around it. I might try the eductors or another powerhead aimed at the surface like suggested. thanks. __________________ - Ryan B "that is enough skimmate to ruin lives." - GSMguy Current Tank Info: 220g Display, 70g sump, 35g frag, 50g fuge, 2x250w MH, 1x400w MH, 2x80w T5, 2x140w VHO Actinic

10/21/2008, 04:36 PM	#10
Breakin newz Moved On Join Date: Mar 2008 Location: New Jersey Posts: 149	Can u get a picture of ur overflow setup? I bet you it is improper setup of overflow, I had the same exact problem and had to redo mine!

10/21/2008, 05:11 PM	#11
dsrich69 Registered Member Join Date: Sep 2008 Location: Norway,Maine USA Posts: 29	the overflow is a two box system, one box inside the tank with slots and one outside connected to the hose to the sump, with a u-tube between them. __________________ 75 gal Reef, sump for 75 gal,built in skimmer, compac lights, 70+ lbs live rock, 3" crushed coral, 2 power heads,, Current Tank Info: 75 reef

10/21/2008, 06:01 PM	#12
Breakin newz Moved On Join Date: Mar 2008 Location: New Jersey Posts: 149	Ah so its the non-perminent ones? If so and if you can try raising it allittle, like I said I had to mess with my height settings on mine for it to skim the surface...

10/21/2008, 07:08 PM	#13
dsrich69 Registered Member Join Date: Sep 2008 Location: Norway,Maine USA Posts: 29	that just raises the tank level __________________ 75 gal Reef, sump for 75 gal,built in skimmer, compac lights, 70+ lbs live rock, 3" crushed coral, 2 power heads,, Current Tank Info: 75 reef

10/21/2008, 07:41 PM	#14
NewBostonConst Premium Member Join Date: Jul 2007 Location: Mi Posts: 94	I take a plastic container and push it down in the top of the water so that it flows very quickly over the edge of the container and fills the container. If you do this a couple times a day for a couple day it will be gone for good. Then just aim a large power head at the top of the water. The scum will also stick to the out side of the container so wash it off with hot water each time. This works really good for me.

10/21/2008, 07:46 PM	#15
TheH Registered Member Join Date: Mar 2008 Location: Bellevue, WA Posts: 1,278	Perhaps your return pump is not powerful enough to force things to get sucked into the overflow. This happened to me once when I had to use a maxijet1200 as a return pump for a few days. The flow is just not powerful enough to disturb the thin layer on top of the water.

10/21/2008, 08:02 PM	#18
Rascal1371 Premium Member Join Date: May 2006 Location: Annandale, VA Posts: 101	This probably isn't it but just to be sure it isn't overlooked -- Make sure there is at least a 1/2" - 1" drop from the tank's water level to the water level in the overflow. I see this happen in my tank when the water level in the overflow rises so the water level in the whole tank is above the weir of the overflow. This means the overflow is no longer skimming the surface.

10/21/2008, 09:00 PM	#20
wrott Registered Member Join Date: Mar 2004 Location: Alabama Posts: 2,912	You probably just need to agitate the surface more w/ a PH pointed straight up--no more film. The "filmate" will eventually be processed by your filtration. __________________ OK, but where does the meat go! ------------------------------------------------ 120g SPS, 125g mix, 56g FOWLR, 20g qt

10/21/2008, 09:10 PM	#21
BuddhaKiss Registered Member Join Date: May 2008 Location: Northern Va Posts: 1,068	I agree with raising the overflow up a lil. It's possible that you're either maxing out the gph rating of the external overflow, or you're return isn't strong enough...either way, the amount of water that is entering the chamber (inside the tank) is too much for the return pump. Basically, make sure the water level of the inside the overflow box is below that of the tank...this should create better "suction" and provide adequate surface skimming IME.