My platy was fine 3 days ago and now since yesterday his scales look like someone tried to take them of with a knife ( like you do when preparing fish) Its siting at the bottom of the tank and has barley the energy to even swim about 20 cm and has to rest, I feel really sorry for it and I don't want it to suffer anymore so what can I do to help it pass away in a painless way as possible its the long weekend so no shops are open till tuesday. Or should I let it pass away on its own. All my other fish are better than fine by the way I think its because he is old.