Filter gunk

[Dadof4]

So, I opened one of my canister filter for it's every other year cleaning (just kidding, don't throw things at me)because I noticed the water flow had decreased over the past week. When I opened it it was full, and I mean full of this slime that I've never seen in a filter before. It was so thick I couldn't tell what filter media was in what tray and I use bio-balls and ceramic rings, I should have been at least able to tell those apart.....Honestly, I crack my canisters open monthly for preventative maintenance, clean the impeller and well, etc. Other than the decreased flow I had no untoward signs of a problem, any one got ideas as to what this was and what the cause is?

[soggydrysuit]

That's the bacteria, I think - a bacterial mat. You could check by putting a smear under a light microscope?

[rengnath]

Does the water inside the tank still look normal? And is any of this gunk on the bottom of the tank?

[Dadof4]

I thought bacterial matting too. I saved a sample to get under a scope to see what it kind it is. now that you mention it, the water had just started to cloud.

[Pufferpunk]

What fish are in what sized tank? I get that but after about 3 months of no cleaning, on a heavily-stocked tank with other filtration that gets cleaned alternately.

[Dadof4]

This is on my GSP tank. 55 gallon with a single GSP, I open the filter once a month for standard maintenance. One interesting thing was the smell, very rotten eggish smell and there was a huge air pocket in one of the filter layers.

[Pufferpunk]

That's one poop'n puffer!

[Dadof4]

Yeah you ain't a kiddin'! I got a feeling it's like Soggydrysuit said, a bacterial mat and not waste product. I'm going it run it under a microscope in the morning. I wonder if somehow the inside of the filter got contaminated with some odd bacteria somehow, possibly from a food source.

[RTR]

Most likely it is just mulm, mineralized organic matter. Originally it would have been fish poop, food scraps, cast-off bacterial and other biofilms, etc., now fully mineralized inorrganics digested by the filter.

I don't open my external bio-only canisters very often - less than you do - but I back-flush them monthly. Back-flushing is done connecting the Python to the intake side of the canister (all have shut-off and disconnect valves) and drawing tank water through via the canister return line. I shake the canister a bit during the back flush to loosen any build-up, allowing it to be drawn out to waste. With that practice, I can go a decade without disturbing the biofilter bed itself. The impeller and its housing, and the intake and return tubing need more attention.

HTH

[Pufferpunk]

OMG, what a fantastic idea!

[Dadof4]

Huh, never thought of that...was there an adapter needed or do your canisters run 1/2 inch fittings? Great idea!

[RTR]

I have adapters to screw onto the Python for the various canister hoses. I don't use but one brand of external canister, all with disconnect valves in both intake and output lines, and use a limited range of sizes, so only need three adapter sizes, Not a big deal, I just have to replace the hose gasket in the close-to-the-end Python coupling every few months because it is opened and reconnected so frequently.

When you run a lot of tanks, you are benefited by redundancy, consistency in filter , and think out labor-saving approaches. The time you save allows more tank...

My canisters are not user-friendly, but they do seem to last forever. My son is counting on inheriting them...

My mechanical filters are rinsed weekly (including the bio-only canister pre-filters). Minimum fuss and bother, because there are no significant bacteria to protect as there are in biofilters..