Sick fish?

Hiya everyone, first post and I hope you dont mind it being a question.

I currently have six mollies and six little orange platys. I did my usual tank clean yesterday and also washed the filter. Before I did this all the fish seemed well, but now I can see that one of the plattys is really not well. He is swimming weird and he doesnt look as bright as he did colourwise. He seems to spend a lot of time just resting on the bottom or on some plants.

All other fish are good. Water is clean. Ammonia = 0, Nitrites = 0, nitrates = 20-30.

Any ideas what could be wrong with this fish?

All I can think is maybe you did have an ammonia spike or something like that.

Did you remember dechlorinator and all the usual things?

Could anything have got in the tank?

Hiya Angel, and welcome to TFF. How long have you had the fish? Have you recently added anything new - plants or fish etc to your tank? Also did you do the fishless cycle or did you just put fish in?

Sorry for all the questions but it might help us figure out what the problem is

Hiya everyone. I havent had the fish for that long, about 3 weeks and I had done the fishless cycle.

Hes just had a bit to eat which is a good sign hopefully.

Hope hes a bit better in the morning Angel. Give us an update then will you?

Hi angel. When you say you did the fishless cycle, how did you do it? Also, did you add all of the fish at once?
As indigoj said.. it's likely you could of had an ammonia spike with it being a new set up

Well the update as requested - the platty died during the night. All the rest of the fish seem ok so I am hoping that it's nothing to worry abot but should I dose the tank with anything just in case?

Oh thats a shame Angel. I wouldnt dose the tank with anything - it would be hard to find something to use when there might be nothing wrong.

I would suggest keeping a close eye on your water stats and the health of your other fish and keep your fngers crossed too!

Did you wash the filter in old tank water or tap water?? When you did the fishless cycle did you leave the filter running and waited a couple of weeks or did you add ammonia everyday??

Hiya phiishy. No I did the proper fishless cycle with ammonia. Took just over 3 weeks but I ended with 0-0 readings and then went and got the fish. Its a 60 litre tank - its not overstocked is it??

I washed the filter in tank water, and give it a rinse through every 2 weeks when I do the gravel too.

Could judt be bad luck Angel. Keep an eye on the rest and see what happens