Some Questions

looks exactly like that, ( the white on mouths )

hi sue only just come online, not the fish are taken from google images but the fish mouths on them pics i was pointing out as similar to mine, even my mums fella said it has the same thing on its mouth like you described it as something caught but looks like a little spot on its mouth

i hope it is nothing shall i just wait and see and keep looking at them? also one of my dwarfs have been half eatne and i dont know why because they all shoaled together never showed signs of anything wrong with it swimming wise etc they all look active yet when i did my water change it noticed it was all white and half eaten and i doubt it just get attacked for the sake of it so this is a bit worrying, some of my glo lights have worn down fins the ones on top of the back but i took it as this could be play fighting or whatever as you say fish do have fish fights etc

so am i best just keeping a look on the fish then or what do you think i should do? also if i missed your answer about the water dechlor sorry but the one you mentioned and the tetra safe one doesnt it get rid of ammonia? just incase my tap water does have it or if its in my tank water from fish food waste or fish waste then the one you have API or the other one i posted about tetra safe wont get rid of it will it ? but maybe its ok seeing as you dont use one to get rid of ammonia i shouldnt need to then i guess?


thanks again sue and if you tell me i cant get certain fish then i wont i always listen lol, them fish were off google images and i remember you saying i could only have dwarf rainbows  , my tank wouldnt be how it was if it wasnt for you MAINLY but also the others that help me too thanks

Don't change your sponges unless they are falling apart. A layer of filter wool should fit on top of the media in the top basket, it is only a few mm thick.

Have you tested your tap water for ammonia? If there is none in it you don't need a dechlorinator that detoxifies ammonia, though most brands do contain a detoxifier. Any ammonia made from decaying food or fish waste will be made slowly and continually so the filter should cope with it. But you shouldn't really have any uneaten food, you should only be feeding just what the fish can eat 


I don't know what to suggest about the fish that's half eaten. It could have been sickly when you got it and healthy fish will pick at a sick one. In the wild, predators are attracted by sick fish as they are easier to catch. The other fish don't want a predator hanging round so they kill the sick one themselves before a predator notices it.
If that fish is in a bad way, you might want to think about putting it down.

Can you write down all the kinds of fish you have then we can look for the most likely biting suspect.

Though the rainbow, all fish will eat dead fish so the damage could have been done after it died.

None of those are known biters. Maybe they are just squabbling amongst themselves. Just keep an close eye on them see if any more damage happens.

from that recent incident the whole of the harlequins tail fin has gone but its still swimming fine, one of the others is getting a white line across the middle of its tail fin and the tip of the fin on the back is white, just dont know if this is a disease or not its the same as the rummies and glo lights