But all the bio filtration your tank could ever need is supplied by a piece of ocean reef rock, and it looks better too.
All these types of products are sold on the basis that more bio available area is better, which is not true. Bacteria will multiply until they are nutrient limited, and then they stop.
Everyone. This is not to replace live rock. This is not to allow your system to “be better by having more bacteria”
My only use for this is to transfer bacteria in a quick, easy, and clean way, to new tanks, with minimum risk of bringing over anything unwanted. Rocks and pot scrubbers get built up with detritus, these are small, easily checked for any hitch hikers, and easy to fit in overflow chambers, all in one chambers, or regular sumps.
17$ got me 3 tanks. That’s 6$ a tank for convenience. Who here is not guilty of spending $6 or more, to make something easier in their hobby? Live rock costs over 20$ a pound now. I got media for 3 tanks for less than a pound of rock. Far from my worst purchase ever