Foam at Surface of Water

[Terrance]

My 120g is forming foam at the surface of the water. What is it? Some kind of skimmate or protein? I have good surface agitation. It started after I got rid of my HOB aquaclear filters. My fahaka is 3inch now and I try not to overfeed 6 days out of a week.

https://www.youtube.com/watch?v=8epyvT8PlU

[Pufferpunk]

Link's no good.

[Terrance]

Try this one. Background noise is dishes being washed. Just put it on mute.

http://www.youtube.com/watch?v=8epyvT8PlUs

[Pufferpunk]

Why is your water level so low?

[RTR]

Either bacterial surface film or DOCs (dissolved organic compounds). The first indicates insufficient surface exchange; the second insufficient water changes or improper feeding.

[J-P]

That is what I thought, but couldn't put the words to "paper" In my 500 gal cascading tank, there was always 1 section that did that. It was the area that had the most torrent. I always had a feeling that it was a combination of the 2 because areas would have that "oil slick" look while others were fine. The "oil slick look" certainly caused improper gas exchange. When I added an extra pump it broke it up. What caused that could have been improper feeding, not enough mechanical filtration or a dozen other reasons.

Too bad they don't make true skimmers for FW tanks

[RTR]

The best I can do is the Eheim surface scum extractor. There is or was another brand that supposedly works/worked well also but I have forgotten who made it.

In my old age I have learned to avoid certain foods and use particular techniques for frozen/thawed foods and only very very rarely have FW surface films anymore. But I have not discarded my collection of the Eheim surface extractors either, just in case.

[J-P]

Tom's has one but for my application it wasn't adequate.

It was far too small. It may work on other people's tanks but it is not cheap $$ to be tossing out there on a "might work".

http://www.amazon.com/Aquatics-Series-S ... 797&sr=8-3

that was the guy I got. It didn't come with the filter like I had anticipated nor the pump; this is just the housing, but it almost worked.

Just keep an eye on those water levels. If they drop too much too quickly the filter is useless. I had mine hanging from a block of 1x1 wood attached to the trim of the tank.

[Terrance]

Why is your water level so low?

Its low for you all to have better view. I showed the surface of the water because it looks like enough agitation to me. If I'm doing my 50% water changes weekly, then it must be improper feeding or not having enough mechanical filtration. I only have 1 Fluval FX5 (~900gph) and a circulation pump (~700gph).

Maybe I'm feeding too much meaty food. Raw shrimp and worms is very common food. Snails when I get them for free from other hobbyists.

[Pufferpunk]

Nitrate?

[RTR]

Nitrate should not have a big influence on the surface films. But it can indicate improper food or food handling - i.e., thawing and rinsing exterior to the tank.

If you have persistent surface bubbles in a corner or wherever, the surface movement/turnover is inadequate, Q.E.D. Fine tuning surface current is a matter of fine-tuning, i.e., trial and error.

J-P: That is not an inexpensive gadget, you are correct.

[Terrance]

My nitrAte is around 10 before water change. The foam is not a bad thing, correct? I hope its not the bacteria stuff that you guys are saying..

[RTR]

Foam is frequently bacterial in origin, but equally may be from DOCs. You can see surface films by highlights on the water surface - like oil sheen on driveways and highways after a shower - if they are DOCs and heavy. Bacterial films tend to show up best when you are putting something (hand or finger or tube or anything smallish which penetrates the surface. You see "wrinkles" and/or "tears in the film" around the object pushing through the water surface.

Skimmers remove this material in SW, but those are ineffective in FW due to the surface tension differences between SW and FW. DOC films also serve as food sources for microbes, which are in turn eaten by larger inverts such that especially designed filter intakes can remove or reduce such materials in FW. But as pointed out in earlier posts, they are tricky and can be pricy.

Visible nematodes in FW are a symptom of high DOC loads (either in the substrate or in the water column or both), as they feed on the microbes which eat the surface films. I have had plenty of issues with such in fry tanks where lots of foods are added daily. It can and does occur even with relatively low nitrate titers, being a function of the particular foods used and the tank upkeep.

[Terrance]

I decreased the amount of meaty food and fed more snails. No more foaming at the surface. Thanks for all the good info everyone. I never saw any kind of film at the surface of the water.

[J-P]

you won't because of the agitation... that doesn't mean it is not broken up and consolidated into the foam. It is the same kind of foam you see at a beach. Only we have the option for manual removal.

That silly "juice" that comes with frozen blood worms doesn't help either...