So I have had my 40 gallon tank setup for just short of a year. There are 2 Tiger Oscars and 2 common Pleco's. I do my weekly cleaning and have an (over) filtrated system. Last week I decided to take out the gravel to see if cleaning would be less of an effort. Since then however, my Pleco's have been acting a bit odd. That is to say it looks like they are trying to jump out of the tank! If I didn't have a full hood, they would've hopped out last week. Is this something to worry about? The ph and other water levels are fine. ***????????***