I wouldn't go that drastic at first. I would just give the tank a good
cleaning.

The bubbles from the substrate is kinda worrisome. That could be nitrogen
gas or even Hydrogen Sulfide caused by Anaerobic bacteria in the substrate.
If you release large pockets of this it could kill the fish. I would take
the cleaning of the substrate slow.


"Mitch Edelman" wrote in message
...

I'm cleaning up a 120 g. aquarium with some severe problems:
the tank belongs to an older man who has health problems and
severely neglected it for what I would guess is close to a year.

The setup is: planted 120 with Eheim 2228 - the filter was pretty
crudded up, having not been cleaned in at least 6 months. The
substrate (4 inches of laterite) has not been cleaned in a very long,
long time: when I used python to do water change and started poking
into it to get detritus, it released a stream of bubbles, which I
have no idea what they were (no odor).

Algae is all over: the glass is covered with something that I thought
might be cyanobacterial, but it did not clear up with doses of maracyn
and water changes. It is green-to-brown and comes off very easily with
razor; it also seems to have some gaseous bubbles trapped or generated
in it - I've never seen anything like this before.

The plants (java fern, vals, some hygro) are covered with a different
algae that feels fuzzy to the touch - it is very short and impossible
to remove. Other of the plants seem covered with something that looks
a lot like brush algae,

Somehow, the fish seem healthy - at least the tank is very lightly
stocked.

I have no idea where to begin on this. I thought to do a complete
breakdown - pitching the substrate and plants, replacing hoses and
filter intake and return, a bleach dip for the thermostat (also covered
with that fuzzy algae). But before undertaking something that drastic,
I wonder what alternatives there might be - any suggestions will be
greatly appreciated.

Thanks in advance -

Mitch Edelman