flashing

Question
We have had a 50 gallon freshwater aquarium set up for about a week now with 6 platys and 6 tiger barbs, and they seemed to be fine until this afternoon when both types of fish started flashing.  They don't do it constantly but do repeat it multiple times when they do.  What could cause this?
Thanks in advance.

Answer
By flashing do mean they are quickly rubbing themselves against the gravel or decor? If that is the case typically a parasite is the cause however on a few other occasions I have seen fish do this when the temprature in the tank was getting higher than it should be. You can also add some aquarium salt which will help reduce some of the stress on the fish and can assist in getting rid of the scatching but a medication for tank is the only sure way of getting rid of it. Best of luck and happy fish keeping.