Help with surface film (eisenbacteria?)

[jweis]

I'll buy it from you if you don't want it. Might be good to use until my super duper home brew unit gets working.

Jim

Sure if you want it. I have the small size. Make sure it will work for you, or I will just return it.

[Jim Miller]

I'll take it! December meeting OK?

jim

[sns26]

I gave in to putting in a powerhead, but I'm really going to cry if I have to add a surface skimmer too. Among other things, I have no easy way to plumb it since all my filter plumbing goes through the tank bottom.

I want to figure out what's at the root of this problem, then attack that. The fact that I have it in one tank and not in the other is the best clue I have so far. The differences in the two tanks are:

Tank with film:
High light
Pressurized CO2
Aquasoil
Lots of new driftwood
Modest bioload (57 gal, 20 small rasboras, 10 shrimp)
Moderately planted

Tank without film:
Medium light
Pressurized CO2
EcoComplete
Bioload that has been all over the place - low and high
Planting that has been all over the place
Very little driftwood, and what I've had was very old.

My current theory is that some interaction between the aquasoil and the high CO2 is causing some sort of mineralization/precipitation reaction at the air/water interface.

[jweis]

I'm certain the dirt-based substrate is the culprit. I only have the surface film with my 11g (gets CO2) and my 5.2g shrimp tanks (do not get CO2). My 37g has a baked clay substrate and no problem.

After running the surface skimmer all night on the 11g, there is no trace of any film this morning. Yippe. One tank down, three to go.

Unfortunatly the air driving skimmers do not work on freshwater tanks, so I will likely get fed up with the film and convert the shrimp tanks to HOB filters. I found a guy that makes surface skimmer boxes for HOBs. Scroll down this link a bit to see the black boxes. http://www.nano-reef.com/forums/index.p ... =0&start=0

Sam, could you run a pipe UP from your drain to the surface, so you are pulling down the film? That really all the surface skimmer I bought does.

[DelawareJim]

No, I don't think it's soil based. I have it in my 110 that is 2-mm quartz gravel, heavy plant load, light bio load, light feeding. High light, both with and without pressurized CO2.

Cheers.
Jim

[jweis]

Hummm, I had myself convinced. At least the new surface skimmer I bought is making a difference. I might convert the shrimp tanks to some sort of small canister filter with a surface skimmer.

Maybe my guppies are eating the film on my 37g.

[150EH]

I don't think it's related to the type of substrate but could be related to bacteria mass in the substrate, filter media, etc. My film was gone but as I installed my new plumbing I upgraded my filters and was only able to seed one filter for 30 days and the day the plumbing went I added a second filter with clean media, the film reappeared lightly. My opinion is it has to do with load vs bacteria vs plant mass and some of these tanks we are talking about are cycled but still fairly new.

One of the things I did the first time around was a bubble wand ran at night, but the bubbles popping at the surface started to destroy my light valance so stoppeded, the other thing I did was a circulation pump aimed to the surface with a very strong ripple, or else a surface extractor will need to be used, but it seems after a couple to 3 weeks and the film is gone.

[jweis]

My film was persitent. I've had my 11g up and running for several months and the film didn't go away until I installed the surface skimmer.