AQQA Aquarium Fluidized Moving Bed Filter, Fish Tank Bubble Bio Filter Media with Air Stone Dissolved Oxygen, Submersible Sponge Filter and Suction Cup for Marine and Freshwater Aquariums Cleaning (S)

Does it's job great considering it is just a tube filled with media and a tiny filter about 1/2 inch thick. I used it as a prefilter so to speak for my aquaponics aquarium set up because my water parameters were horrendous and tank just would not cycle and lower the Nitrites. Once I put this in in about 2 weeks water wasn't as green, water parameters have been perfection, the beneficial bacteria are going to town on nitrites/ammonia, and fish all survived. I love this thing and would recommend it to anyone that wants a low tech tank. Easy to use and easy to clean. The media it comes with does the job but I'd recommend adding ceramic media if this is your primary filter. I also suggest getting a 5w air pump, I used a 3 w i bought befre reading the instruction manual. It still works just fine with 3 W but more power might help suction. For my setup, wasn't an issue since the plant media is technically my filter, this is a back up to assist with the filthy goldfish poo and my pleco who's also filthy...As a bonus, watching it is kind of mesmerizing, the media just flowing and spinning around in the air bubbles. its like an aquarium version of a lava lamp

Great value for a bacteria guest house! Make sure you understand that this isn't a polishing filter for your water. If you've done a bit of research in fish keeping this is for beneficial bacteria growth/housing real estate lol. I put it on a aqua culture pump with 2 outlets and put a splitter on it to run both into the single air inlet. Took only about 1 minute of the air moving through for it to catch a rythem. Works as advertised! Don't expect bacteria to grow on it right away. These things take time!

I'm new to the fish hobby so if it changes I'll update. With all the products available I like the fluidized bed with K1 media the most so far. It has the most surface area to hold beneficial bacterial; it has a prefilter sponge that can be removed easy to unclog. I am curious how much tank water flows through the device in an hour. The plastic bottle I used as a diy version seemed better until I realized the poor quality plastic would ultimately hurt my fish. This is a better option for safe filtering, and it's more attractive.

Simple to set up. Performs its particular task well.. took a few days for all the media to start really moving around inside, but after it starts building up some beneficial bacteria inside it gets churning. Using it in an axolotl tank along with a sponge filter. Seems to really do the job while also putting some oxygen in the water.

I put this as an extra filter to go along with another filter in a 40b. It takes a day or so for the bubbles to get the media to move properly... but this really is a great filter. Impressive!

The media could not be loaded.  Still too early to see how well it works, but so far it has been perfect. I I squeezed out one of my old filter sponges when I put it in to help jump start it's bacteria colony, so far all my tests are coming back with pristine water!

Pretty good bio media filter. I bought the small one in my 5 gallon tank. It works great but i have noticed that some of the media is breaking down and floating into the tank. I have it in a tank i am cycling.

Absolutely awesome moving bed filter! Works great the media spins freely and evenly. I'm using mine in a 20 gallon grow out L046 zebra tank! Very good quality will be ordering more for my other tanks!