Hikari Bacto-Surge High Density Foam Filter, Large

I've had them in my tanks for a few months now as have had no issues. They are your run of the mill sponge filter. They do come with filter media to add in which is a nice touch.

While it's a great sponge filter (no doubt about that!), it may not be what you're looking for. First, it's HUGE! I underestimated how big it is. I have a heavily planted 40 gal tank with driftwood and had a difficult time getting it wedged in there. It's never coming out. Second, if you want small aerating bubbles, this isn't it! The bubbles are HUGE too. I may try the airstone hack I've read about. I bought this to use as backup filtration and aeration with a battery powered pump for power outages as I live in hurricane alley where we can lose power for days! (I lost a few fish after Hurricane Florence).I had no trouble getting it to sink. Read the directions and you won't have a problem. I soaked it in a bucket of treated water for an hour with intermittent squeezes.TLDR: It's huge and has large bubbles. Soak it first to get it to sink.

I had never heard of this type of filter before, but my daughter who is OCD about perfection did. So we added one to her 40 gallon Aquarium. She has a lot of live plants and the water was always murky. Not anymore. Within 2 days, crystal clear and the critical water measurements come back great. Couldn't be happier!Pro's:Actually clears up the water from live plant water tints, murkey, and the little amount of dirt from the play sand. The circulation filter did not!No noiseinexpensiveeasy to cleanCon's:Big and can be an eyesore in a smaller tank. Surround with plants if you can.See pics. The one pic with the thermometer is also for the thermostat review.Please note that we added this to the regular type circulation filter. This did a much better job clearing up the water.

Great product. Bigger than I expected but thats ok. The inner chamber does not fit an air stone, but by clipping with some scissors you can make room for one. Kind of a pain to tailor but they work great overall. They do sink after a few days of processing water, or if you squeeze them. There is room for an air stone and filter media or a long air stone after clipping the inner framework. It can be hard to fit an air stones through if you do not clip the inner plastic/faming wide enough. I have not experienced any weakness to the overall structure after my edits. It fits together like legos.

I love these sponge filters. I have canisters and HOB filters on my tanks but also add these sponge filters as secondary filters as they are more reliable and last a long time. If I ever have a power outage then I can easily throw a battery powered pump on these filters and should be fine until power is restored. Don't fool yourself thinking sponge filtering is ugly and outdated (undergravel filters are what's outdated and a huge risk to your tank) it's really the best way to go!

This works wonderful. Nice addition to tank to Lee water clearer and oxygenate the water for myLittle lovelies 🥰

The Hikari Bacto-Surge filter sponge is actually smaller than the Aquapapa/generic aquarium sponge filter is that I've been using in the past, which cost about 5 to 6 dollars less than the Hikari-- and they seem to be upon a close back to back/side-by-side comparison the same PPI of foam. The Hikari filter is at least one full inch shorter, which may not seem like much but certainly lowers the surface area for beneficial bacteria to build and keep my tank balanced and cycled. The worst part is that the sheep sponges that I have bought in the past have been much easier to use with air stones! You can check online videos, and the innertube for the Hikari filter sponge simply does not work properly if you are going to do some modification and add airline tubing and and and air stone. I had to use leftover plastic pieces from my generic sponges to get it to work. Definitely not going to purchase this Hikari sponge again!

These are my favorite filters! Seems like these work better than most! Would purchase