# floating slime/oil in my planted tank



## eatpanda (Jan 27, 2010)

There is like a slime/oil subsatnce floating on the top of the water in my tank. Does anyone know what this could be? I have 5 live plants and one snail, no fish yet.


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## endgin33 (Jun 10, 2008)

I had the same thing when I first started my tanks- it is protein or something similiar on the surface of the tank and is not really a big deal. I.E. its harmless and won't kill anything. You can strip it off of the top of the tank by putting a paper towel on it and pulling it off.

BUT- it can mean a few negative things as well. Mostly these things matter when you are supplementing CO2 (especially pressurised Co2), but the explanation can be helpful even if your not.

It can mean that the surface of the tank is not getting enough circulation to move the "stuff" around and this can be quite important to the overall success of planted tanks. Planted tanks don't need quite as much water movement as reef tanks, but for similiar reasons benefit from good water movement (i.e. fresh nutrients are bathing the plant constantly- co2, nitrogen, phosphate, potassium, etc...) As I have gotten better at growing plants, I have found that they go nuts when they are swaying to the rhythm of the currents... Its like they want to go dancing! This can be prevented by having good circulation- whether that means having a large filter than you probably "need" or by adding supplementary pumps like a Hydor Koralia to move the water around, you will generally get better results growing plants if the water moves well.

The other problem that you run into when the surface film builds up is that that gas exchange has become a problem. That stick film means that oxygen is not going smoothly from the air to the water. If you supplement CO2 this may seem counter intuitive ("I just spent all this effort and money to ensure that their is extra CO2 in the system why would I want it to get away? Or- "I heard that I can't use a BIO-Wheel on my tank because it will agitate the CO2 out of the water...") but in my experience "more" gas dissolved in the water overall is much better than just more CO2. This can be real problem if you are adding a alot co2 to the system and then the lights go off. Plants release co2 at night and the one-two punch of the plants respiring at night (releasing Co2) and bad gas exchange equals dead fish sometimes. But just as importantly for the planted tank geek is thazt plants WANT some O2 at night and if that isn't happening they have a problem.

I hope that I haven't gone too far with this explanation- like I said film won't hurt your plants or fish most of the time but it can mean more.


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## eatpanda (Jan 27, 2010)

would a pump be better for circulation? i have one i just didn't use it.

thanks much


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## eatpanda (Jan 27, 2010)

what can i do?


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## londonloco (Sep 25, 2005)

I had the same problem on my 29g. I put a Koralia powerhead in the tank and pointed it towards the surface. It took literally minutes for the surface to appear clean. I use Excel in this tank, NOT pressurized co2.


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## eatpanda (Jan 27, 2010)

would a pump work?


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## Shad0w (Nov 13, 2006)

why don't you add surface skimmer?


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## eatpanda (Jan 27, 2010)

maybe but would a pump work? air pump...


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## londonloco (Sep 25, 2005)

Try it, couldn't hurt. I would think you would need to have the "hair dryer effect" going on. Let us know if it works. I was going to add a surface skimmer, but the powerhead was in my house, and in this hobby, free is better than buying something new.


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## eatpanda (Jan 27, 2010)

What is surface skimmer? My guess is that it will just go away once i add fish.


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## aquabillpers (Apr 13, 2006)

That happens to almost everybody. It is harmless. It can be removed by sliding a paper towel under it. Eventually it goes away, unless you have a more fundamental problem.

If you insist on spending money to combat it, buy some mollies. They eat it.

Good luck!

Bill


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## medicTHREE (Feb 5, 2010)

eatpanda said:


> What is surface skimmer? My guess is that it will just go away once i add fish.


Doubt your fish will change it at all.

A surface skimmer is a filter attachment that sucks from the surface to remove this very thing. Some filters have this built in.

The likely cause of this is your water conditioner. If you use one that has "aloe" in it for "slime coat" then it just ends up floating on top. Conditioners like prime or chloram-x will not do this. Most others will. Fish food can be the culprit as well. BTW, for common dechlorinators, prime is the way to go. 250 ml bottle treats 2500 gallons(most 250 ml bottles of other products treat less than 1000 gallons for the same price) If you are ok ordering online, Chloram-x is by far the best bang for the buck.

http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=12703


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## grak70 (Jan 5, 2010)

Another easy solution: turn off all agitation in your tank when you do a water change, invert your siphon hose and point it at the surface. If you can get it to form a whirlpool without breaking the siphon, you'll suck all the scum off in short order.

I get this stuff too. I have found that liquid ferts tends to exacerbate the problem in the absence of a lot of surface agitation. It's very difficult to eliminate completely, but I concur with previous opinions: it's mostly a nuisance. Other than causing a very minor drop in light intensity, it has no effect beyond aesthetics.


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## eatpanda (Jan 27, 2010)

couldnt i just leave it like it is and just keep putting paper towels on it daily? I mean you people say that it is harmless. Are there any fish that would eliminate it besides mollies?


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## medicTHREE (Feb 5, 2010)

You could, but the cost of paper towels will end up being more than the other solutions......... And you never get rid of all of it with paper towels. It is harmless but it bugs the piss out of me and obviously bugged you enough to ask about it.


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## aquabillpers (Apr 13, 2006)

eatpanda said:


> couldnt i just leave it like it is and just keep putting paper towels on it daily? I mean you people say that it is harmless. Are there any fish that would eliminate it besides mollies?


Sure you could, and eventually the problem will go away.

You can buy a lot of paper towels for the cost of a skimmer. 

Bill


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## londonloco (Sep 25, 2005)

I thought surface scum also cuts down on the oxygen exchange in a tank....no?


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## medicTHREE (Feb 5, 2010)

Yes it does cut down on gas exchange. The surface skimmer I liked can be had for 12 bucks shipped. Hard to beat for crystal clear water surface.


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## aquabillpers (Apr 13, 2006)

Yes, it does cut the gas exchange, but not by a significant amount.


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## medicTHREE (Feb 5, 2010)

Bill, I'm going to disagree. In my 75g riparium prior to using the surface skimmer, even with the spray bar pointed towards the surface(center of tank) the thick protein film caused my fish to gasp at the surface. Simply using a cup to skim it off made the fish better, but in hours it was back and they were gasping again.


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## aquabillpers (Apr 13, 2006)

medicTHREE said:


> Bill, I'm going to disagree. In my 75g riparium prior to using the surface skimmer, even with the spray bar pointed towards the surface(center of tank) the thick protein film caused my fish to gasp at the surface. Simply using a cup to skim it off made the fish better, but in hours it was back and they were gasping again.


Hi, Medic!

Disagreement and discussion about it is always good.

But the dynamics of a riparium differ from that of a planted aquarium. For one thing, the volume of water is much less. For another, there is a greater chance for material to enter the water from the dryer areas. Because of the smaller water volume, there is a greater chance for O2 deprivation.

In the case you cited, it is quite possible that the agitation cause by the water removal supplied enough O2 to meet the fishes' needs, at least for a while.

I grant that it is possible that a very thick film on the surface of the water _could_ effect significantly the exchange of gas, but the kind of film that is often found in aquariums is just not thick enough to do that.

If in the case you cited, the film actually was preventing gas exchange, there is another issue there that needs to be addressed.

Bill


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## medicTHREE (Feb 5, 2010)

aquabillpers said:


> Hi, Medic!
> 
> Disagreement and discussion about it is always good.
> 
> ...


My 75 g riparium is filled to the top, not partially. It is in the journal section. It is also grossly understocked currently.

I have seen a heavy protein film effect tanks of many sizes, this was one I chose to cite.


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## NatalieT (Mar 20, 2007)

eatpanda said:


> couldnt i just leave it like it is and just keep putting paper towels on it daily? I mean you people say that it is harmless. Are there any fish that would eliminate it besides mollies?


Guppies. (I never see any film on the surface when I have guppies in the tank, but when I've only got cory catfish, the scum appears again.) I suspect my platties may eat it too, but since I've only had platties in a tank that also has guppies, I can't be sure they do anything about it. I've had guppies without platties, so I know the guppies work. (That's "lots of guppies," not "just one in a large tank" to remove the film. Of course, if you start with just one who's female, you'll have lots very soon!)


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## EQUINOX (Nov 19, 2008)

I have this damned problem as well.
It mainly causes aesthetics issues:

Co2 bubbles tend to stay "unpopped" on the surface
Lights' penetration is mildly damaged

I have also found that liquid ferts and even more than that - rich protein fish food causes it.

Regarding the surface skimmer - it causes the deprivation of CO2 enriching the water well enough. There's much agitation to the water leading to CO2 "leaving" the water since it "oxygenizes" the water (when it drops in the pipe).

Good luck.


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## rich815 (Jun 27, 2007)

medicTHREE said:


> Yes it does cut down on gas exchange. The surface skimmer I liked can be had for 12 bucks shipped. Hard to beat for crystal clear water surface.


Yup. Mine works great. Nothing else worked. Now the surface is crystal clear.


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## medicTHREE (Feb 5, 2010)

EQUINOX said:


> I have this damned problem as well.
> It mainly causes aesthetics issues:
> 
> Co2 bubbles tend to stay "unpopped" on the surface
> ...


No sure what surface skimmer you have seen but their is minimal surface agitation and "oxygenizes"... The pipe is full of water, so there is no drop. THe surface has a tiny bit of vortex where is is sucked in. THere is no air/water contact inside the pipe at all. If this was all the surface agitation your tank had, i would be worried about adequate oxygen.


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## EQUINOX (Nov 19, 2008)

medicTHREE said:


> No sure what surface skimmer you have seen but their is minimal surface agitation and "oxygenizes"... The pipe is full of water, so there is no drop. THe surface has a tiny bit of vortex where is is sucked in. THere is no air/water contact inside the pipe at all. If this was all the surface agitation your tank had, i would be worried about adequate oxygen.


We're a bit of topic here..
Anyway, I don't have a filter pipe directed to the surface causing only a mild stream.
That's enough, the rest (and it's a lot) is contributed by the flora.
I still think (and have learned from one's with more experience) that it causes some CO2 loss. The beneficence though is what makes it a minor drawback to most people.


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## medicTHREE (Feb 5, 2010)

And again, i am saying that I have used it on several tanks and found no co2 loss that is noticeable.


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