Pls pls can you stop adding fishes..... letting them taste your graveyard is very cruel..... 40fishes?? you are scaring me, IMO remove all fo your fish at once... start your tank PROPERLY...... recycle again, get proper test kit and pls pls stop adding fish.... you dunno how much harm you are bringing to the fishes.... We remove somthing from mother nature, and we should provide the best care for it and not dump it in a poorly setup tank..... Sell away all your fish or put them up for adoption.... Do you know damel are tough little creature and they will survive almost any tank condition and thus seldom death of your livestock doesn't mean your tank is good enough.... Ad you notice i say the word surviving and not living happily or thriving....
Also this hobby does not come cheap.. if you want everything to do well, be nice and get good comment from everyone be prepare to have a deep pocket.. If you want to save on everything and anything... i suggest better dun start the tank better.....