20-55 gallon

No complaints at all! I can't believe you get 2 complete filters for what 1 sponge prefilter often costs. They work great. In fact I have one in a 10gal with some shrimp guppies and angels, and one in a FIFTY FIVE gal with angels acera gourami a loach and some danio. It is keeping up so far. The air pumps are tailored to each tank- so small cheap Wal-Mart pump on the 10 and decent size dual outlet on the 55 only using one outlet to run the filter. Ultimately on tanks over 10-20 gal these probably make a better supplemental filter but using one on my 55 while I work on my canister filter is proof of concept. They seem to cycle very quickly and be fairly responsive to bioload demands. Grow out tanks, shrimp tanks, tanks with small fish or betta these are ideal. They are also extremely simple AND allow you to have another point of aeration and circulation. I put the pickups in areas where water wouldn't always be moving super well (behind big decor, corners) and they help keep it all clean. Shrimp love to pick off em, my botia likes to hide under/behind them.The outlet is adjustable in height. It fits in my 10 and the outlet gets pretty tall probably about 18 inches total.Everyone should have one running. If you get Ich, have fry, any reason you need another tank like, *now* these are great. Put water in. Warm it. Drop in an airline and sponge and it's ready to keep your fish safe.

I bought 2 of these and 2 new aquariums for invertebrates and absolutely love them. I have not had an aquarium for years and maintaining the filter was my biggest concern until I learned about sponge filters. These are perfect for breeding tanks and nano species. beautifully light and still feel tough, not to mention easy to clean when you do a water change, simply squeeze it out into the old water and replace...literally takes 15 seconds and the sponges have shown no sign of decay or breakdown after 6 weeks of shrimp and crayfish picking at them. Will buy again, awesome customer service from the company as well. Buy with confidence

I have these in a 30 gallon long/breeder (36" long 18" high). They cleared out the dust from the sand really well. I have both hooked up to the same normal air pump, the further one doesnt get as much air as the closer but it still pumps. I'm not sure I'd trust one of these in anything larger than a 20 gallon when used by itself. The back of the packaging has some spelling errors haha but they're cheap and work so can't complain.

I'm going to preface my review by saying I'm rather new to the hobby of shrimp keeping (got a 13-gallon tank for Father's day, and was hooked immediately). I went out and purchased all sorts of things I didn't need, and several sponge filters (since it's what everyone says to do). They were both bigger sponge filters with weighted bottoms, but I still wasn't happy with what I was working with.I took a chance ordering this model, and I'm thrilled! Not only does this fit all my requirements, but you get 2 sponge filtration units (2 units, 4 sponges, 4 suction cups) for such a minimal price! I'll list my pros/cons below:PROS:It's light-weight, and has parts that can move in different directions (which is amazing when you're dealing with a small tank like I am). Even the part that releases the bubbles (not sure of the official name) can be extended/retracted to suit the size of your tank, as well as turned whatever direction you want the bubbles released! The sponges (intakes) can be moved independently from one another (even though they're attached to the unit), and my small shrimp seem to enjoy hanging out on them (fine-mesh sponges, so the micro-particles of food cling to them). Best of all, and I've mentioned this previously, it's VERY cheap and you get 2 units!CONS:None for me. In all honesty, I thought the unit was going to be difficult to place (because it's not weighted), but the suction cups hold it in place wherever I want it! I'm not even bound by the unit being vertical because of this; I can put it any direction I'd like, and swing out the sponges to suit my needs!I'm not kidding - please give this one a shot. You won't regret it!

This could very well be the best sponge filter for a tank with filter feeders. There is enough sponge material to hold beneficial bacteria. And the shrimp will actually graze the sponge for edible material after the filter matures.I use this filter in a tank with shrimp and clams. I find that the shrimps get most of their food from grazing the surface of the sponge. The air-driven filter does not over-filter the water. This is beneficial for those who keep filter feeders, like clams and some species of shrimp. Clams cannot compete with the power filter. They feed by filtering the water for edible goodies. Goodies to them are floating algae, bacteria, and micro-organisms. The water in most fish tanks contain very little of those because they are over-filtered. A sponge filter does not remove these floating bits as aggressively as a power filter.This is a copy of an old Tetra design from 30 years ago. It has passed the test of time. Yes, the suction cups will lose their hold in a couple of years. Sooner in hard water. For hard water, I recommend the ATI sponge filters. They do not use suctions cups but instead are freestanding. However, a freestanding sponge filter with a weighted bottom takes up a lot of space on the substrate. Space that could be used for plants.Highly recommended for invertebrate tanks.

I have ten running tanks ,all use sponge filters. I thought I would give this a try in my 30 gallon. Save your money. After 24 hours debris was still floating in the water after my water change. Provided great water movement, but the sponge is way to fine or there isn't enough suction created to effectively clear the water. Will be returning.

Really pleased with these filters. Nice large sponges and great output. These are in my shrimp tanks and are perfect for shrimps. Will definitely buy again.

Product arrived in perfect condition and seller was awesome answering questions. Product is good quality and should last for years!