UNEAK 2-Pack Large Premium Pre Filter Sponge Aquarium Intake High-Porosity Foam Roll Fish Tank Shrimp Beta Baby Fish Replacement Foam Cover Filtration Freshwater Saltwater 5-20 Gallons Easy to Clean

Easy to install and cut to size, cleans easily. Keeps shrimp from getting sucked into the filter. Does not impede filter’s function.

Works well,cut to size

works well help clear my tank.

These worked great on our small tank we use for baby fish

Fits well and Easy to clean.

The size was right for my penquin 150 and cascade filters. Bigger/thicker than I thought, but great for storing beneficial bacteria and preventing fish/fry injuries.

Fits my filter Perfect. Really like the corse sponge.Great for shrimp and small fish. Highly recommend

Sponge PrefilterI'm not usung it as a prefilter on a HOB (hang on back filter) intake. I hated the inevitable rattle that HOBs developed, since I have shrimp, so I stipped using them eventually. Even while I had them, I needed a prefilter sponge thing anyway once I started keeping shrimp. And that got me interested in sponge filters, and once I added a sponge filter to my tank, I was kinda addicted... so I'm running like 3 store brought sponge filters, 2 have at home made extension sponges, and 1 home made sponge filter in my 75g tank. My bioload is pretty low... 1 bristle nose pleco, 1 ancient gmo tetra (yes I know they are schooling but I'm not rehoming it at this age, I'm not replacing the rest of the school which it has outlived, I'm just letting it live on in an environment it's been used to for years), a few elephant snails, a devil spike snail, some nerites, and a thriving cherry shrimp colony. There's a bunch of live plants.I wanted to make a simple small sponge filter to have ready in case I want to set up a simple q.t. tank for incoming new snails or shrimp, and I suspected this would be a super easy conversion from something to slip over the HOB intake into a sponge filter. Literally all I had to do was poke a small hole near but not at the top of the cylinder and stuff some air tube through, put on an air stone, and stuff that to the closed bottom of the cylinder. After that, I gave it a try in the tank, but it sorta floated, so I dropped some of the expanded clay balls down the cylinder (I use them as substrate in the flower pots I keep the plants in). That keeps it on the bottom of the tank. If you're not familiar with sponge filters, they generally rely on bubbles rising in a container to sort of drage water along with them, and the sponge allows water to come through it to join the upward flow through a central hole. (Sorry I'm not great at technical descriptions). The awesome part about sponge filters is the large amount of surface area they provide for the beneficial bacteria dealing with the harmful stuff in the water (way more important than straining out chunks of junk, the ammonia to nitrite to nitrate process is super critical to the health of the tank.... because it takes toxic stuff and makes it way less toxic). The beneficial bacteria mostly live on surfaces, not free floating so sponges are awesome.I love this sponge so far, it has a slightly less dense porosity than the rest of the foam/sponge materials in my other filters but it's still not seeming to trap any shrimplets. The shrimp love grazing on the sponge filters, and this one is no different. I like the size because it isn't taking up tons of space in the tank, and if I needed to take it out and set it up in a q.t. tank, it won't be too big for a 5 or 10g tub or tank. It would be able to take its established colony of bacteria with it from where it usually lives in the main tank to the just set up q.t. tank and get a jump on getting that cycle established in the fresh tabk. It should be just as easy to squish and swish the acumulated excess debris from the filter as with the rest of my sponge filters. I just make sure I scoot any shrimp off, disconnect it, take it out of the tank, and then squeeze it repeatedly in the bucket of water I just removed as part of my water changes (so far I'm able to maintain a water change every 3 weeks ish and the tank is doing ok--over bio-filtration, low bioload, and lots of live plants). Once it's less grubby, I put it back in and reconnect the air tube. (don't rinse in tap water if it's not already treated to remove chlorine!).Even if you do use this with a HOB, having a prefilter sponge is great for your tank because most HOB companies urge you to change those floss and carbon cartridges every month ...which I stiopped doing after having a HOB for a year or two because I learned that's a lot of my beneficial bacteria being thrown away and then my tanks ability to convert waste products from the tank inhabitants and uneaten food (e.g. ammonia, toxic stuff) gets a serious set back until the bacteria repopulate and recolonize the new cartridges... and then I throw those away. Even if you still change out your HOB cartridges, with the sponge pre filter on the HOB there's much more surface area with the helpful bacertia still living on it to keep working on processing ammonia ...I'm definitely happy with this product.