Hiding in the corner

Question
Hi

I have a fairly big tank, its about 180l tank. I have a veriety of fish in there ranging from angels to neons. sometimes when I buy fish they hide in the corner of my tank behind my filter and heater of they stay in the boat and I dont know if they eat anything. I currently have 4 black fish that swim upside down and im not sure what they called but they are hiding in the corner and in the boat. I have also had elephant nose fish and they too have hid in the corner. what can I do to keep them from hiding in the corner and get they to swim around the tank like all the other fish?

Answer
The fish have to feel comfortable to swim around freely.  If they are new to the tank it could be overwhelming and their stress level may be high. Try leaving your aquarium light off to reduce stress. Only turn it on when showing somebody the tank...unless you have live plants.