Although they say this can be used for a 30 gal tank, not so much if you have a sand substrate. The power is great for making waves and circulation, but unless you have a gravel bottom, it will blow your substrate everywhere. I would recommend for a tank at least 40g or larger. Not the quietest either, but not unbearable, I switched to the Hydor Koralia Nano

i bought this for believe it or not my 55 GAL reef tank for just that extra circulation along my back wall. i put it where i wanted and decided to trade it out with my bigger one i have in the front product works great! wish my petco by my house still sold them i would buy another!

I bought this for a 29 gallon fresh water aquarium for circulation at the bottom of the tank for some wood shrimp. It's fairly compact so I was able to camouflage it with some plants. The shrimp love it, they don't often leave the current. I also have a plecostomus that likes to swim up to it and then ride the current backwards. Works great for the price.

Awesome power head, perfect flow for 15 gallons or less. I use this in a 10g reef set up and it does the job perfectly

I bought two of these for my 20 gallon saltwater tank. For the price they are made of cheep material. The power head has a large distracting suction cup with a latch on it. The latch is supposed to allow you to disengage the suction cup. The latch gets stuck and the first time I tried moving it, it broke. The power head has a small ball that goes into the suction cup rig but upon adjustment it breaks leaving the ball in the suction cup. This is the second that has broken on me. NOT worth the effort, time, or money.

This circulation pump is perfect for the Biocube 14. It adds just the right amount of extra circulation without being overly powerful.

Purchased for a 29 gal biocube. Ended up trying it in my 5 gal. pico. I figured it would make a mess. But after a couple minutes everything settled down and is working out great in this small tank. The only negative for me? I have to buy two more!