Rated 4.7 out of 5 by 3
Rated 5 out of 5 by Jonisupra Cermedia Bio Block
After reading so many reviews and also seeing my lfs use them in their tanks I decided to give it a try as my nitrates were always high, it's been 2 weeks since I added it to my sump and all my parameters are great, no detectable nitrates or phosphates in my tank. Highly recommend it to anyone who have nitrate problems.
November 15, 2015
Rated 5 out of 5 by Robbiehaus Great buy!
High surface area to help your nitrification, can go on back of the weir or waterfall where I place it to receive optimum oxygen
November 14, 2015
Rated 4 out of 5 by TheWookie Seems to work
I have split the box and used these in my 95g freshwater tank and in my FOLR salt tank while I sort out my sump situation (temporarily using a canister.) In both cases they seem to work well. On my heavily stocked fresh community tank, I used to consistently get .25 ammonia, 0 nitrite and 5 - 20 nitrate using the API drop tester. With the bioballs removed and the spheres installed, my ammonia has been 0 for three weeks, nitrite 0, however, nitrates have gone to 20-40 ppm. I guess the increased nitrate is a by product and ok as long as it won't go higher. I am a consistent water changer and filter cleaner every third or fourth weekend.
March 25, 2015