Grey slime in tank - what is it??

[SnowLeopard]

I have a small tank at my office, and the last time I did a tank change, I noticed a grey slime in the "off-stage" portions of the tank.
In the main tank, the environment looked normal other than the water was somewhat dark. However, in the water pump, tubing, and filtration areas of the tank, the system was almost clogged with a grey slime that smelled.
I don't know what I'm dealing with (algea or fungal?), or how to treat it.
Any help would be appreciated! Thanks!

Tank details:
5 gallon tank with a water-fall topper (provides aeration and filtering)
5 tiger barbs and 1 catfish (not sure of type)
No light or heat source (at this point)
Currently the PH is "off the chart", but I'm trying to get it down to normal

 

[OrionGirl]

The slime is most likely a heavy bio film. Most tanks have this to some degree. Normally, it isn't a problem other than requiring regular maintenance on the filter and tubing.

 

[SnowLeopard]

I have 1/2" tubing connected to my water pump, and the water flow was almost stopped due to the grey slime. Is that normal for bio film?

 

[TKOS]

You do have a pretty heavy fish load for that small tank, so maybe that is causing the heavy buildup. Get some pipecleaner and clean out the tube is the best bet right now.

And definately get a heater for those guys to keep them healthy. (and make sure to get a thermometer as well).

 

[SnowLeopard]

Thanks for the help!