CerMedia MarinePure 1.5-Inch Sphere Bio-Filter Media for Marine and Freshwater Aquariums, 2-Quart

Great product highly recommended!!!

Great product. Very satisfied!

Great product but the balls seem to drop a bit of sand type bio material that gets in the sump..not too bad though.

Exactly what I was looking for.

Expensive but I think it works great in adding more surface area for beneficial bacteria to live. Round balls also allow for good water flow through.

Very good quality work very good

Excellent quality product.

Fits perfectly into the reservoir on my fusion 20. They also expedited the cycling process immensely.

Very good product. Working Just like described.

Very porous. Seems to do well and the sphere shape does not hold a bunch of detritus. I have minimal rock in my tank so these are doing a good job allowing bacteria to propagate and a nice home for various small critters.