XY-380 Aquarium Fish Tank Biochemical Sponge Filter, 4-1/2-Inch

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 doesn't 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.

UPDATE: its been about half a year since I got the first one for my 40gl. I must say, its doing a much better job than any other filters that I've used. The water is ALWAYS crystal clear and its so easy to clean the filter. I just bought another one since I will be moving my goldfish over to an 80gl. Also, I must say, they also do a good job doubling as an air stone as they keep the water moving and oxygen flowing through the water. Its cheap, and its totally worth it.I found out about these thing via youtube and wanted to try it out. I love how its cheap, durable, and good for my goldfish tank. I'm hoping this will help save money since I've been spending 100s on just 2 goldfish alone. If anything, its unable to clean up the floating poop, but I can easily scoop that out with a net. Plus, a whole lot of it gets sucked out during water changes. I like the size and cheap pricing. I'm definitely getting more of these in the mear future

How did I not find these sooner? :VBasically, just get these instead of air stones. Do it. It's literally aeration AND filtration of small particles & baddies in the water.Ever since I slapped these in my tanks, they're crystal clear.The basic concept of these: it's submerged in water, an air hose is attached down the center of it; air is pumped through the hose and is forced back upwards through the clear plastic tube that extrudes out of the top (which is removable). With this, aeration happens with bubbles. However, what's truly happening here is due to the forcing of water down and up through the sponge, water is being sucked in by this sponge, and thus that's where your filtration comes into play. It sounds crazy, but it works wonders.In regards to "how well does this thing sink": When you get this filter, don't run tap water on it to "clean it" -- grab a bucket, and put some of your fish water (from the tank this is going in) in the bucket, and then put this filter in it. The trick here is to actually squeeze the filter a few times and it'll sink on its own! Magic! This sponge DOES have a weighted base, so it actually can be in a bare-bottom tank just fine. Just remember to squeeze your problems away, sorta like the commercial... yes.Good purchase! 10/10, my mollies do thank you kindly

There weren't really any instructions but it after googling some other sponge filter setups it was easy to do. With my new baby axolotl this creates a wonderful environment that has filtration but very low current. She still goes up and climbs on the filter to play with the bubbles though! I do wish there was room to easily add an air stone since the bubbles coming from mine are pretty big and a little loud. I'm sure I can figure it out reading through some more reviews and researching a bit more. Overall a good buy, a nice cheap alternative to an over the back filter that works well in tanks that need low flow for animal comfort!

This is the best sponge pre filter i have tried with AquaClear 70 Power Filter - 110 V, UL Listed (Includes AquaClear 70 Carbon, AquaClear 70 Foam & AquaClear 70 BioMax Excelllent biochemical filtration.Due to the extra surface area, it continues to flow well even after 4 weeks of straight use. And this cleans the water so well that i rarely have to clean the filters in my aquaclear. It also prevents any pieces from causing impeller damage. This keeps it running quiet also. With other smaller pre filters i would get clogged in three days. Ive used this for 6 months and working well.Although the filter tube on the aquaclear 70 is too big to fit in this. So i took the plastic tube out of this filter and stuffed it with extra sponge material to create a seal.

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 doesn't 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.