HI to all online I am having the most bazaar problem EVER

I have ran my tank for 12-18 months with malawis, recently I purchased 4 new malawis and plants for my tank. Within 24 hours I was loosing fish I ahve lost in total 12 fish My amonia and nitrites are through the roof and cant seem to get them down at all. Over the last 2 weeks ~I have done three 50% and 5-8 25 % water changes and still very high my fish are not dying as ofetn as they were but cant seem to reduce the high amoania and nitrites

ANY ADVICE OUT THERE FOR ME PLEASE???

NEAL

Strange

How big is your tank, what filtration and how many fish have you got in there?

Sorry about your fishkeeping troubles.

Is it possible that one or more fish have died and are trapped among rocks or ornaments? Could something else have died, like a large snail? Could there be a large amount of uneaten food in the tank, trapped out of reach of the fish?

Is the filter working and not clogged or broken?

If you now have less fish than before and the ammonia and nitrites are still high, it is unlikely to be overstocking. I think the source of ammonia and nitrites is something in the tank.