Help, dying fish!

[Nikb]

Just found one of my Pakistani loaches dead on the bottom of the tank and being eaten by a glass shrimp. I saw it earlier this evening and it looked fine. I was away for yesterday and most of today but my girlfriend's been looking after them for me. She said that yesterday she thought it was dead but it was just sleeping.

I've had a look at the other fish and one of the black phantoms has become an albino! Also his dorsal fin has been nipped (don't know what by) as has one of the lemon tetras. The fish don't look distressed except one lemon tetra that was hovering slightly lopsided.

I've just checked my water parameters and there's no ammonia or nitrite, nitrate is 12.5. I haven't got a pH testing kit. The air pump is working fine, I did a water change on Thursday and hoovered the gravel too. Could it be that I've got some hydrogen sulphide pockets as I don't get to all of the gravel?

If not this then what else could be going on? I have a bad feeling that I'm about to loose all my fish but I don't know what to do.

 

[Feline]

For now just do not more than 30% water change and add some streecoat to the water.

When u said the dorsal fin being nipped, is it like a bite? or is the fin wasting away? Other fins like tail fins etc are ok?

You posted in earlier dates about the swollen abdomen ... is it on the same loach?

How long has the tank been set up for? What's ur gravel cleaning routine?

 

[Nikb]

It's actually the other pakistani loach. It looks like a bite and one of the lemon tetras has the same. The phantom's colour has come back now which is a relief. The tank's been running for a couple of months almost now. I clean the gravel weekly but I can't get to all of it because of objects in the tank. I've added some stress coat already but haven't changed the water.

 

[Feline]

It's rare for hydrogen sulphide to form in gravels cause there would still be water flow between the gaps of the gravels. I've had gravels in the tank and like u, I don't hover all the gravels because of the ornaments, plants etc. Didn't have such kind of problem neither.

Any other opinions on this hydrogen sulphide thing, guys?

But it's good to hear the color has come back on the Phantom. I'd say keep an eye on the fins, see if they'll heal. If not there may be other issues than fin nipping.