Situation
I bought thr tank already set up. 55g with only a heater and an hob filter. 1 fish, 2 hermit crabs, 2 snails, 1 Cc star. 1 2lb live rock, 5 lbs sand, aragonite substrate.
She said the tank had been up and running 2 months. Hadnt done any water changes since starting.
I started...