Surface Scum

[blizzack1]

Hi Guys,

As some of you may have been following, I've recent setup and stocked a 48 gallon mbuna cichlid tank.

Everything has been going fine thus far, with the exception of some surface 'scum'.

It was quite pronounced when I first set the tank up, as some vegetable matter spent a few days on the surface of the tank while I was away, but I cleaned it out and it mostly disappeared.

My water conditions seem fine test wise (PH, GH, Ammonia levels all where they should be), so I'm wondering if this is something I should be worrying about, or if it will go away over time?

Thanks for the advice,

Josh

[repeej]

What kind of filter do you have?

By adding an air stone the bubbles will break the surface and should prevent "scum" from forming on the surface.

[Nelson]

The only problem with surface film, apart from the unsightly part, is that it restricts gas exchange.  As suggested, an airstone, or ideally a surface skimmer would solve the problem.

[blizzack1]

What kind of filter do you have?

By adding an air stone the bubbles will break the surface and should prevent "scum" from forming on the surface.

I have a Fluval 304 Cannister, but its several inches below the surface (I scratch my head when reading that the output nozzle should be at or above the water line?  It would have to be above the rim on the tank, no?).

I'm kind of new, so is an airstone something I can attatch to the output nozzle (is there a technical term for this?)?

[BigDaddy]

Point your spray bar so the water comes out at a slight upward angle.  This will ripple the surface, which should limit the protein buildup.

[Aiglos]

I had the same problems;  I have 2 xp3s but cannot point them upwards as it disturbs my arrowana;  I used a airstone and I havnt seen it since;

[darkdep]

The scum can be removed either through agitation (airstone, or as many have suggested altering the direction of your filter outflow), or by the use of a surface skimmer such as this:

http://www.bigalsonline.ca/catalog/product.xml?product_id=25207;category_id=2631

I have this on one of the canisters on my 90gal and it does a good job.  No scum!

[repeej]

darkdep:  how does that surface skimmer work?  I can't figure it out just by looking at it.

[darkdep]

A regular intake is basically a tube underwater that sucks water up.  Imagine a sideways T; with each side of the T being an intake.  One side is below water, the other side has an extension that follows the surface level and sucks water from the surface.  This way, rather than just deal with the scum by breaking it up, this method actually pulls it into the filter.

It has an adjustment to control the amount of suction from the top vs the bottom intake.

It's not commonly used; I am not sure why really.  The only downside is the price...for some reason, $17.99 seems a lot for what it does to me.  

Another issue is that the more you suck from the surface, the less is being sucked from the bottom...meaning you're losing the benefit of the intake being low in the water.  On my 90 I currently have 3 canisters running, so I don't mind dedicating one to surface water...just a thought.

Another option...many people, especially with rocky Mbuna tanks, have a canister and a HOB to help with Mechanical filtration.  The HOB generally agitates the surface enough to prevent most scum.

[repeej]

Thanks for that...

[kitten]

I have a Fluval 304 Cannister, but its several inches below the surface (I scratch my head when reading that the output nozzle should be at or above the water line?  It would have to be above the rim on the tank, no?).

The nozzle doesn't have to be above the rim of the tank, just high enough to ripple the surface of the water.  This will help with the scum that you are building up.

I'm kind of new, so is an airstone something I can attatch to the output nozzle (is there a technical term for this?)?

An airstone is something that you connect to an airpump.  It doesn't connect to the filter.  If you pick up an airbar instead of just a stone it adds a nice curtain of airbubbles to your tank.  My oscar seems to like swimming through the bubbles

-S