Water surface looks oily, how do I clear it?

[grimlock3000]

I have been waiting this out for a few months now. The water surface of my 26 always looks like I spilled a tiny drop of oil in the tank. Well, it looks more like a really fine power, but move around like an oil. The stuff just stays up there and make my water surface look bad when you look up at it. The tank is fully cycled and has been for a long time. My AC200 is set to fulkl so it dumps a good ammount of water on the surface. I was thinking about just blasting it with a powerhead for a while, but it will come back eventually. I have no idea what it is, but think it comes from the Omega One flakes I feed since it seems to be extra cloudy when I feed the fish in the morning.

I do 25% water changes a week, feed once a day, and only put dechlorinator in the water.

[QTOFFER]

I get the same thing occasionally - I also think it's from the flake food. I was able to skim it off with a clean paper towel. Viva brand is my favorite since it's so strong and cloth-like. Whatever you do, don't use cheapo supermarket-brand towels - I did and they made a linty mess.

[grimlock3000]

I will grab some Viva papertowels next time I go to the store.

I would like to feed my fish just pellet food, but I have some small feeder Guppies in the tank and a Cherry Barb fry that can not fit Bio Blend in their mouth too well. I might try some New Life Spectrum pellet food for small fish.

[skys]

thats odd doesnt that usually happen when theres not much water flow?
i never knew food could cause it

[QTOFFER]

Yes, skys, I only notice the film swirling in the one small corner of my tank where there is little surface agitation. I use Ocean Nutrition flakes and I suspect it's the fish oils in the food, but I may be wrong. I don't overdechlorinate and I don't use aloe vera in the tank - two other things could also cause a surface film.

Like grimlock3000 said, it only looks bad when you look up at the water surface. This is probably another 'flaw' that only the regular caretaker would notice since most people view the tank from eye leve or above.

[nemokeeper]

I had the same problem on my tank using my Fluval cannister filter. I replace the intake pipe with a surface skimmer type, Hagen makes one that you can adjust whether it takes it from the bottom or the top. Used it and hour later oil film gone.
You need to have water skimmed off the top.

[mgkaelen]

i have the same problem, however i don't feed that tank flakes at all.... it's live plants so i try to keep the surface agitation to a minimum though for the plants sakes. ... is this harmful to the tank?

[grimlock3000]

I do not think the surface film is harmful to the tank at all. Just unsightly...

At some point I am going to make my tank fully planted and was planning on a surface extractor. Now I might get one early...

This usually just happens to planted tanks usind CO2 supplementation. Form what I've read, it is a film of proteins. I get it off and on in my 90 gallon, it was gone for a long time, but came back.

Those surface extractors work really well, so far as I've heard.

I've also heard that Mollies, and to a lesser extent, swordtails, will eat this scum layer. Never tried it, but thats the word on the street, so to speak.

[TheMadNucleus]

My Thoughts on this.

Yep - this stuff is predominantly protein complexes that result from the ecosystem. They are attracted to the surface because they easily combine with oxygen and therefore gravitate toward highly oxygenated areas of the tank (the surface). This is the whole concept behind a protein Skimmer (i.e. for Marine Tanks). By creating thousands of tiny bubbles the proteins seek the surface area of the bubbles - where the oxygen is. The bubbles therefore have a surface tension that allows them to be collected as a foam in a cup.

Since Freshwater aquariums can not use Reaction chamber Styled skimmers (it is the salinity that provides the bubbles resiliency) this solutions does not work. However, by using a surface extractor you are in fact employing the same concept and in effect you are using a protein skimmer - the only difference is that the skimming is being done at the surface of the tank instead of in a reaction column (or chamber). The Scum that is skimmed from the surface is excellent food for the bacteris in your Biological filteration.

Bottom line on this is that I think the sump approach for freshwater tanks is a very good approach because all of the things you really want to biologically and chemically filter reside on the surface.

For my next FW tank I will use an overflow/sump approach, use a canister to suck the water from the sump, filter it and return it to the tank.

Scum-be-gone approach

Tom

[Allivymar]

Excellent thorough description Tom; thanx for explaining the science behind it. Have a few kudos

Btw, Bedford Hills? My bro lived there about a yr ago; I'm over in Ossining! Yay Westchester *grin*

[TheMadNucleus]

Allivymar,

Thx for the Kudos. Great to see a neighbor on here. I looked at many houses over in your neck of the woods - really great place - came very close to living there.

Agreed: Yay Westchester (the second most expensive county in the states )

BTW - your photos are great. Some really nice angles - love that pleco too.

Tom

[Enki]

I think almost any tank will get 'some' film, but with agitation in a FW tank it wont be very noticeable or problematical.

I hate it though, so I am planning my next tank with a corner overflow tank mod.