I was wondering if anybody uses these type of blox? I've seen them at Big als. They say it supposed to have more surface room for bacteria to grow then bio balls. I don't know if they are worth it. They are really spendy.
they are actually cheaper, you dont need any where near as much, I use the 1x9x9 sheets of it they sell, it is a glass sponge like material, I use 2 sheets ($30) for my 125g tank and they handle it just fine with 6 mde to large pygos in it.