Tetra Whisper 4 Gallon Internal Power Filter, Filtration for 1 - 4 Gallon Aquariums

I have 3 tetra 1.5 gallon betta tanks with this type of pump filter system. I found one of my tanks drained half out. Checked tank for leaks, none found. Last night 2 of my tanks leaked half their water out. My guess is the filters get plugged and force the water out the back hinge side of the filter cap and then down the power cord somehow. The filter slids in and out easily, and the cap snaps down tight enough to seal the filter sides so the water is forced thru it. But when filter is not changed once a month it will plug and water can only exit under cap edges. Some people have complained that the cap will not close all the way. I had to trim the edges of 1 filter with sissors so it would slide in all the way or cap would not close. My filters were used for 3 months before they plugged. Hope this helps someone understand why their tank suddenly leaks out half it's water.

The filter works exactly as it supposed to. BUT it doesn't have suction cups. After spending 2 hours looking through Tetrs web sight and 4 phone calls, I give up.