Hi, I've had a tropical tank up and running for a few months now, and it started off quite well. The last month has seen quite a few problems, with some mysterious deaths, most of which seemed to be isolated cases with no common trends

Death toll so far includes (in order of death);

2 female guppies

1 platy

1 neon tetra

1 female guppy

1 male guppy (only just reached full maturity but with great colours) he will be sorely missed

I've only just joined this forum as of yesterday and am trying to gain some understanding into whats happening.

The male died 2 weeks ago following a big water change and a tank cleanup, i took out an undergravel filter, changed gravel, retaining 50% of the water with the fishwhich which i returned to tank after clean. Male guppy showed signs of tail rot which wasnt picked up until to late, i added melafix to little to late and he expired within 2 days. I completed 7 day melafix course just in case and did 25% water change on saturday. Had water tested monday, amonia, nitrite and ph all tested perfect.

Just noticed today that 2 female guppies arent right. 1 has a deteriorating pectoral fin and red gills, the other has red under gills on only one side. Both still active and feeding happily but this seems reminiscent of one of the females that died. The deteriorating fin is getting worse as i think a male guppy is nipping that location. Going to isolate her in a birthing cage as i don't have a 2nd tropical tank. Any ideas please?

Hi there, what other fish do you have in the tank? Do you have any bullying or fin-nipping species?

Good luck with sorting it out...

What size is the tank (cm or inches), what filtration do you have since you removed the UGF (and did you have the other filter up and running a good month before removing the UGF) and what fish are still alive?

Hi again

It's a standard 2 foot tank; 24*12*12, current filters which i have been using before and after the removal of UGF is a tetra whisper 10 in tank filter and an Elite stingray 5 in tank filter.

Fish still alive are;

2 BN catfish

2 zebra danios

1 platy

1 cobalt blue goriami, (very placid)

5 neon tetras

3 male guppies, 2 of which are spotted, these guys seen to harrass the females alot)

5 female guppies

15-20 baby guppies from 2 different hatches, about a month between hatches.

I removed the UGF as i suspected and rightly so, the guppy fry were getting under it and unable to get back after growing to big.

None of the fish seen to be nipping or harrassing others except maybe the spotted male guppies. The danios did when first introduced 2 months ago but have settled down nicely.

The platy that died went off his food and hung round the surface a day or 2 before dying, the neon i found dead after doing a head count and i found him under my lump of driftwood.