Review on UPETTOOLS Aquarium Circulation Powerhead Wavemaker Pump: Efficient Submersible Fish Tank Pump - Delivering Optimal Water Flow with Adjustable Suction Cups by Amber Marie

Good for the price. It's a speed as others have said. This works in my tank as I have an external sump that returns through 4 returns that the flow rotates through to change the water flow. I needed the extra flow rate to create flow at the bottom of my 3ft tank. Since this pump is almost at the top, I have no problem mixing the sand below, but it does hold dirt in the water column until it goes into the overflow system in my sump. Happy with the pump except for the suction cups. I wish it had a magnet system but for my tank it is 1" acrylic and therefore needs a strong magnet. As a result I have to clean and replace the pump during my weekly maintenance cycle. I also have one of these pumps in a 75- gallon tank and she is too strong for this tank unless you have sand and very active fish/other stuff I've had my 12000lph for 3 months oh even when it starts it vibrates a bit, before it settles down otherwise the noise level would be unacceptable in my tank setup.