uxcell XINYOU XY-380 Aquarium Fish Tank Biochemical Sponge Filter, 4-1/2-Inch (1-Pack)

this filter is not heavy enough to stay put...itll start floating. I had to put a small rock on top of it in order for it to not float

These things are well worth it at 3 bucks a piece dont know why I never knew about this sooner

Little lackluster when using just an airline. Attached a 450GPH power head on this and easily clears a 55gal.

I solely use this on my 20 gallon fish tank with 2 gold fishes and algae sucker. It works great with a pump. I usually just top off the tank every few weeks and its been working well. Ive been using this type of filter for at least a couple of years now.

I have 75 gallon tank and I purchased this sponge filter $8 and also a HydroAquatic sponge that was $16, the HydroAquatic is about twice as wide as this one and it is grey. I love this sponge over that one because the quality of the sponge is better and it is black and doesnt look big in my 75 gallon tank. I have it on a powerhead but it also works with an air pump. I am definitely going to buy more of these so that I can replace my canister filters which are such a hassel to clean because they are so big (5 tray with UV sterlizer). I recommend this sponge filter to anyone who needs filteration, it is cheaper and easy to manage.

Good buy!

I think this is the best filter for my bettas. Keeps the water crystal clear. Easy to install.

Product arrived ahead of schedule. Its working great ! I would recommend .

I had purchase this after I thought my other was bad. It was the filter. The other sponge turned the water pink. I washed it thoroughly before placing it in the tank. It made the water come out much clear.

Nice and cheap and very modular so if you wanted to make a monster filter, you could just pull these apart and build one that was 2, 3 or more foam high. Got a tank that is 5 feet tall and want a monster foam column in the back? Just buy a few of these and make your frankenfilter. Just remember to get a pump strong enough to drive it. Now for the people who are worried that it doesnt come with an air stone. All you do is GENTLY pop apart the filter and then grab a few things. You will need some cheap air stones and a little bit of aquarium tubing. Once it is apart you clip out the tube from the bottom section (you can feel free to clip the bottom grill that holds the tube) so there will be space for the air stone. When you are done you should be able to stick your finger through the bottom piece without issue. Once you have done that cut a short ~3/8 piece of aquarium tubing and place it in the bottom of the top part so the air stone will have a sung fit. You could also glue the air stone but then how would you chance it when it plugs up? Once you have fitted the air stone and made sure it is snug reassemble the filter. The picture should give you an idea if these instructions were confusing. If you want to use one of these as a prefilter for a canister or HOB (Hang on the Back) power filter price compare the foam refills as you will not need the internals.