Film on top of water.

Hello again, I'm back for more advice lol. So within the past three or four days, I've noticed a few things with my 29g biocube that concern me. There is brown algae growing on the sand next to the glass. I've had a brown algae explosion before, but this stuff is different. It looks slimy and seems to come off in tiny "sheets". The reason it's coming off the bottom is little air bubbles form and pull it free. I've been told to vaccum the sand but would like to get other opinions. The tank is a few days under a month old and my stats have been pretty stable in the past week. Temp: 78, Salinity: 1.023, Ammonia: 0, Nitrite: 0, Nitrate: 0, Calcium: ~520. Today nitrate rose a little but no more than 5ppm.

The second thing I noticed is that I have some sort of film on the surface of the waterm its pretty noticeable when the water is stirred by the powerhead. I'm thinking its just water tension but I think its been getting worse. I considered oil from my hands but I don't think that would be enough to cover the entire surface. I have one of those rotating nozzles that replace the one the biocube came with and its pretty evident every time it blows water to the top of the tank.

There are now quite a few "sheets" of this algae floating at the surface, should anything be done about this? Is this cause for concern? Any help would be awesome

 

Completely missed a thread that already asked the film on the surface question. Mine is a little different though. The film is a new appearance, maybe a week old. I cycled with damsels and fed them the entire time and the protein skimmer has been running. I'm thinking of removing the activated carbon filter and letting more water flow. Good idea?

 

fixxxery2k

I think both problems can be attributed to flow
the film covering the surface are protiens - they bond to the water surface / surface tension in the same way they would to bubbles in the skimmer
but whilst they are trapped by the surface tension the skimmer cant get at them

the algae sounds like cyno bacteria to me , and again this enjoys the relative calm of low flow areas

If it where my set up , I would add another power head to increase overall flow around the tank - but aim it at the water surface at an angle so it breaks up that film and puts it back in water column where it can be dealt with by skimmer

addition of more flow
coupled with a syphoning away of the cyno on the sand bed
should help to reduce/ prevent this issue in the future

Steve

 

I have another powerhead, that's aimed at the side of the tank and it breaks the water surface at the point that where it encounters the side of the tank. Maybe I'll go buy a better one...

 

fixxxery2k

what is the combined turnover of the power heads you have? either in litres or gallons per hour

Steve

 

369GPH. The stock pump is 243 and the additional one is 126.

 

As a side note: don't stick your nose in the protein skimmer collection cup...

 

Fixxxery2k

Sounds low to me, your tank is 29 gallons and you have 370 GPH of water movement

I would increase that to about 20 x tank volume in turnover so 580 GPH would be a good start and even that might be a bit low, depending what you want to keep in there in future IMO

a Korallia Nano rated at 265 gph - to replace the small one you have will give you
about 20 X
and that way you can keep the one you have, and add it back in future if you want to increase flow again for some coral species

Steve

 

Thanks Steve! I'll be going to get one tomorrow from the LFS. You're awesome

 

So the day after I picked up another powerhead, a coralia 1. Its sitting on the opposide side from the overflow grate and points at the surface. The film issue, however, did not get any better. The only way I can get the film to go into the overflow is to remove the physical filter. Does anyone know if removing the filter cartridge is OK to do? Should I remove the filter part and keep the activated charcoal? The filter gets clogged very quickly, maybe three or four days. Should I just keep putting new filters in there?