Thanks Colin_T, for your reply.... My NITRITE is on 0 same as ammonia level, I change watter every week some times even 5 or 3 days but dont let it go over a week... What do you mean to get rid of those 2 fish how? lol ive have flashed down the toilet my sword tail fish once coz it killed 2 of my neons i was angry abit but i wouldn't like to do it ever again its abit cruel i guess.
But i do like neons allot coz they dont take much space and produce less waste in compare to those other one black widow or black skirt tetra. I dont know maybe if some one lives in London i would be happy to give them away or somth but not sure.