AQUANEAT Aquarium Sponge Filter Breeding Fry Betta Shrimp Nano Fish Tank 4pcs (Middle up to 20Gal)

I'm 49 and have been an aquarium hobbiest since I was six. My local aquarium store manager talked me into a sponge filter after years of using underground, canister, and hang-on filters. The 4-pack deal on these was just too hard to pass up. Currently running one as my sole source of filtration on a 29 gallon stocked with approx 30 fish--10 each of Tiger Barbs, Serpae Tetras, and Zebra Danios.Ask yourself, why do fish stores almost universally use sponges on their tanks, entrusting hundreds of thousands of dollars in fish inventory to their operation? Answer: It's the only system that provides fantastic biological filtration in a simple, bulletproof design. Power goes out, your $500 canister filter doesn't come back on, and the clock is ticking on your fish as the oxygen quickly starts to dissipate. The biological filtration on a sponge never goes off. Your fish can survive for days, even weeks if the pump is tripped.Second question: Then why aren't sponge filters more popular in the aquarium hobby? A sponge filter is a single component joined by a tube to a pump. The filter, tubing, and pump (plus an air stone and check valve) will set you back about $20 and last for years. A canister filter costs anywhere from $100-$500, has about 50 parts that can break, and requires regular maintenance and/or replacement of the filter and media trays. Plain and simple, sponge filters are not popular because filter manufacturers can't make money off them. Why would the manufacturers and by extension pet stores try to sell you something you'll NEVER need to replace?A few words about the negative reviews. One guy says they never sink. FALSE. Drop it in your tank, let it soak for an hour, then reach in while the sponge is submerged and give it a good squeeze. It will drop like a rock.Another reviewer says they're loud. FALSE. I modified mine with an air stone to make the bubbles smaller, hooked it up to a Tetra Whisper pump rated for a 40 gallon tank, and it's practically silent--infinitely quieter than the hang-on filter it replaced.Yet another reviewer complained about the lack of directions. Well, that's a problem only if you're living in the year 1994. YouTube is your friend. Within about five minutes you'll know everything about sponge filter installation, including how to do the air stone mod.Some legitimate drawbacks? Minus the air stone modification, I feel the the bubbles are too big and the system is noticeably louder. For the manufacturer to suggest that an air stone is not needed is like a mechanic telling you your car doesn't need a muffler. Secondly, this is a big, beefy filter. If you're into an aquarium looking as natural as possible, a giant black sponge in the corner isn't the most aesthetically pleasing of tank decors. And lastly, if your light source is close to the surface of the water, the mineral deposits from the bubbles will build up pretty fast on your light cover.

They work great! Easy to clean the sponge filters and keeps water clear. I'm so happy with my purchase!

These are very large. Lots of surface area for beneficial bacteria to grow on. Fabulous value for the money. Sponge is not too big of pores - love this product

This thing is awesome man! It sinks relatively quickly, and also has lots of power.I've been using one for about 2 years now, only cleaning it once a month. I'm surprised it lasted this long, and the filter is still running fine! Amazing product for anyone looking for a nice filter. It is a little big though.

These work really well. I use them for my fry growing rack. Could be a little heavier on the base but overall they do what they are supposed to.

These came so well packaged and were extremely high quality. Looking forward to putting them in my tanks. As a side note, if you are just starting with sponge filters- this is what you want. Well crafted, good weight, and seem like they are going to perform above and beyond expectations. Already have another set in my cart.

This is a great deal for 4! They are great quality!

Great price, but a couple things - there isn't enough weight to hold the filter down unless the filter media/sponge is also full of water. Not really a problem because it's supposed be. If you're impatient, just squeeze the spong under the water a couple times and it'll sink. Been using these for a while now and no other complaints tbh. Obviously there are better filter media sponge filters out there, but these are great for the price!