Pump Noise

[lakefish]

I just bought a 72 gal bow front drilled tank. The setup was complete and I am not sure of everything that I have. I have an under cabinet pump pro aquatic pro clear wet/dry 75 gal pump with a protien skimmer. I noticed, after a few days that there was a cyclic noise and that the water in the overflow was going up and down as this noise occured. Could anyone help?

 

[junnie]

I had this same problem. WHAT i did to stop it was make my hose a stright run from the overflow to the sump. Move your sump to the other side. What is happening is that you have to much of a bend in the line. the water is building up in the bend, then it gose down. Making that nosie.