i recently bought a poly-resin decor for my tank, i soak it in water for 2 days before putting into the tank . but aft 1.5 days my endi die, i do an immed wc, but the next day my del also die. can anybody tell me what happening? 
symptom: they become swollen b4 they die.
12.5" endi (rip)
10" del (rip)
8.5" oscar
4" rainbow shark
75g tank
ammo: 0
nitrite: 0
nitrate: 20~40ppm
I couldnt provide the other reading as i dun have the test kit.

symptom: they become swollen b4 they die.
12.5" endi (rip)
10" del (rip)
8.5" oscar
4" rainbow shark
75g tank
ammo: 0
nitrite: 0
nitrate: 20~40ppm
I couldnt provide the other reading as i dun have the test kit.