Am I Doing Something Wrong... ?

[KatieB1991]

So I've had my tank 125 fluval roma set up for about 3 months now, ive had the fish in it with established filter media as it was in my old tank.. but for the 3 months i have had no problems at all! not one disease nothing... not even bulling, all the fish work great together!

But yesterday morning, i found one of my albino corys was missing chunks out of his fins and his smaller fins are almost gone... at first i thought nipping but none of the others seem to have anything wrong, plus i have male guppies so would have thought they would have been subject to fin nipping before the corys. I now think its fin rot, after some research i bought melafix and am now treating the tank with that, but the cory seems to just want to sit at the bottom at the front of the tank, very still, they are still fairly young so the rest swim around the tank like looney's... How long with it take for the melafix to kick in?


I do a weekly water change of 20% (sometimes more), vacuum the substrate, give the filters a wash in the old water.. they also have live plants and a bubble wall. So how did i manage to get such a poorly cory? The rest of the fish seem totally fine and no signs of fin rot?

Any advice would help...

Here is my Tank stocking (if it helps)

7 Albino Corydoras
6 Platinum Tetras
3 Neon Tetras
8 Male Guppies
2 Bristlenose plecs

Help me please

 

[lloyd]

If it was fin rot it wouldnt just happen over night. do you ever test your water? you shouldnt be cleaning your filter out weekly. it just needs a quick rinse once a month or so in water. byt cleaning it weekly you'll be damaging all the nitrifying bacteria colnising it. if it is fin rot then your cory may be stressed or its immune system weakened which corresponds with dirty water.
If your water is showing signs of ammonia then a 20% water change a week isnt going to be doing much.

Also if it is a nippy fish it quite possible could be the guppys doing the nipping

one last thing, your shoal of neons is to small as they need to be in shoals of at least 8. in the wild they will shoal in there hundreds