Fluval U Underwater Filter BioMax

The Fluval U Undewater Filter BioMax works as expected with my Fluval U filters. This is the largest packaging of it that I have seen, so I always buy it here on Amazon because of the price versus getting it at the local fish store. I have Amazon Prime, so I get Free 2-day shipping and I don't have to pay for shipping on my orders which is very nice.If Fluval made these in a larger package volume, I would buy that.Make sure you only remove half your bio media when you clean or make changes in your filter so to make sure you maintain a decent established bacterial content in your tank to maintain a working cycle. Don't wash or clean under the tap, or the chlorinated water will kill off the good bacteria especially on the bio- media you are keeping in the filter. Rinse with tank water if necessary.I definitely recommend these for your Fluval U Underwater Filter. They are the BioMax media that you use with the filter. You can add other things as well into the cartridge chamber like carbon, zeo-carbon or ammonia removers if you need it. Fluval has them available for sale as well, and they are available on Amazon.Fluval Carbon, 100-gram Nylon Bags - 3-PackFluval Zeo-Carb, 150 Gram, 3-Pack Nylon BagsFluval Ammonia Remover, 180-gram Nylon Bags - 3-PackMake sure you are buying the correct BioMax bio media. These are often mistakenly confused with the larger BioMax Bio Rings which will not work or fit in the Fluval U series underwater filters.

The Fluval U4 does not include enough ceramic media, so its a good idea to pick up some extra if you buy one. One box is more than enough to fill up the cartridge and seems like its better quality than what came with mine even though its the same brand.The ceramic media comes in a net/ mesh baggie which has to be cut open to use it in the U4, or can be used whole in other types of filters. Its nice media, its porous and the pieces are just about the perfect size and shape for medium sized filters, I've used it in several different filters now both loose and still bagged.

The media could not be loaded. They work for my cichlids tank is definately cleaner

This is great!

I replaced a hanging filter with this.So quite and works beautifully

I bought this for my Fluval Edge and although it is basically loose in the box I managed to figure out a way that works for me and my tank.After rinsing it very well, before replacing the old biomax, I cut some white replacement filter foam that is way thinner than the original Fluval filter foams and fold it in there so its not loose in my grey plastic filter holder.I can't put too much because there is limited space in the holder for everything the tank needs but I get enough in there that works out well.I would recommend and buy it again.

It comes already in a mesh bag, so that is nice. I was worried I would have had to go out an buy one, but it comes included. There are nice and porous. Good for my aquarium

Works well