Bio Sponge Filter for Betta Fry Aquarium Fish Tank Up to 55 Gal, 3-Pack (L)

I have a 60 gallon tank with fancy goldfish in it, and these are wonderful. I put two inside my tank, HOB filter on back, with a dual air pump and two air stones to help dampen the noise, and they're perfect. They help circulate oxygen, which the fancies love, and they are another place for good bacteria to cultivate in the tank. Clean them every few months and you're golden. Highly recommend, especially with high bioload tanks or tanks you want to breed babies in, as they cannot get sucked into the sponge filters.

Serves the purpose and a great price

Small and great on 10 gallon tanks. I only wish it was available with a coarse sponge.

Ease of use: This filter was so easy to set up, all it needs is an air pump and tubing. I haven’t messed with it since! Fish health: This thing has survived countless illnesses in my tank, and still hold an amazing bacteria balance Ease of cleaning: I’ve had this for 3 years now. I almost never need to worry about the water quality! Totally recommend

These are working well so far. I may modify them in the future though. First off, I cleaned and soaked them in warm water for 24hrs just in case to remove any manufacturing residues from them as you should any product, but especially so aquatic pet products. After that inoculated them with proper nitrifying bacteria and put them into service. The only down side so far is that the air release holes at the bottom of the air tube are so small salts in the aquarium accumulate relatively quickly and reduce air flow, which causes cleaning in my case in as little as couple weeks. I may start by open the holes a bit to lengthen the air flow time frame (note this salt issue is normal and not because of the filter itself.). Secondly I may do the “air stone mod” (look it up online) to these filters just to simplify efficiency and slightly quiet them. Although personally for me they are not loud at all. They have been in use for few weeks now and have NOT killed any fish or other craziness others have mentioned, but again I take steps to reduce issues in the first place.