ok, im using a 10 gallon tank with a Tetra EX20 rated for 10-20g. I got it since it was the most quiet i could find (the top fin was really loud). Well there isnt a control to change the flow of water and it pumps it out fast and i think it might be blowing my fish around in the tank. I know if they swim infront of it, it blows them away (small fish). What should i do. I tried sticking a coarse sponge in the tube, but it gets loose and doesnt work more than a few hours.