Brightwell Aquatics - Xport-BIO Block Aquarium Filter - Biological Filtration Media for Bacteria Growth, Nutrient Control & Control of Unwanted Nutrients - Aquarium Water Treatments, 4 Pack, 1.5 inch

Works really well and fast. Happy with purchase.

This works very well for my Bio-cube 30 gallon. Would recommend this product

It melts. It’s in the back of my all-in-one in an area without turbulent flow. I’ve had the brick in my tank for 6-9 months and it’s 50% melted to fine sand on the bottom. It hasn’t even been touch in that time.It’s fine, it was going to happen based on reviews, but it is an ordeal to clean out.

This says a 4 pack of 2” bio cubes. It comes in a 3 pack. This should be corrected… but it is still cheaper then In store.

It works well but disintegrates after 6 months of use. I'm going to have to switch products because it's crumbling into my sump

I mean it's bio media, I'm guessing it works as advertised to add beneficial surface area. I used it in a reefer 170 with minimal rock work.

seems like the water quality is doing fine for the fish but some corals are dying. Bought these blocks to get a bacteria bed that was better then when using bio-balls. Cant complain

These seemed OK at first, but after about nine months, they are all disintegrating and falling apart, leaving a beige powder all over the tank. For the price, I expected them to last longer. If you are buying these, expect a useful life of about 9 months. I would not recommend.

You can feel the weight difference between this and marinepur instantly and same goes for the porosity I am now a brightwell fan :). I have 6 cubes in the sump for my 150 gal display (reef) 200g total water volume and highly stocked. Would recommend to any reefer.