Hi all

just some advice please

i have a aqua ar 850 tropical tank
I have been letting the tank run for over a month ,so i took some water to be tested yesterday all was fine so i got my first lot of fish to stock my tank.
I got 6 neon tetras- done the "put the bag in the water for 15mins keep lights off ect".
Once i realised them they where fine however i noticed one was not stoping with the group so i kinda knew he would die anyway i got up this morning and i could only see 4 one has vanished i cant see it BUT the other was STOOK in the filter tube so i tried to get him out and ZOOOOP its been sucked up into the filter the filter is a sealed unit do you think it will be ok will the fishes disolve ect i know i will need to keep testing the water what you think?