Hi, i have a 55 litre tank(REKORD 60).I don't know if its my imagination,but the spray bar seems less powerful than it was a couple of months ago when all the equipment was new. I remember it used to create quite a few bubbles,now it creates a few small bubbles,and slowly stirs the surface round. Anyone any idea just how much agitation is needed.Thanks very much.Oh and one more thing, the pipe that sprays the water out has a small hole near the bottom, I was thinking of blocking it,so that more pressure comes out the top.Does anyone know why there is a hole in the pipe.Cheers