CerMedia Block Bio-Filter Media for Marine and Freshwater Aquariums, 8 by 8 by 4-Inch

Good price, the product was well packaged, I was satisfied with their service

Excellent

Does exactly what it says on the tin. Recommend for small tanks. Arrived very quickly. Excelllent seller

My first reef tank was suffering from high nitrates and phosphates despite me using a reactor with carbon and gfo plus macro algae in my sump so i decided to try the marine pure block to help things along a little. I also added a little more macro algae and a dedicated sump lamp, left it all sit there and apart from changing the carbon and gfo let it do its thing. After about 3 months my nitrates which had crept up to 50 had dropped to between 2 and 5! This product seems to work well as a part of my nitrate removal project and my algae problems in the DT are well under control. How much the marine pure block has contributed to this is debatable but as I mentioned, all is good when used as a part of my nitrate management project.

next day can not be better

Three out of four useless

I'm happy with product but i believe there made of PLASTIC !! Upon reading description on back off box it says there plastic. If I knew that I'd probly thought twice about paying 40 pound on them and gone for a cheaper option from a local shop. Don't get me wrong I do love em but the description on web site should say what there made off

The picture is seriously how this arrived today! The block is broken safe to say it will be returned and won’t use again!

Bought the large brick as I have used MarinePure for years. I used 3cft of it in my koi pond shower and used it in multiple fresh water set ups as well. I ordered this for my reef tank and as expected it is a great biological filtration choice. It does its job due to its porous design however it doesn't handle rough shipping well. My brick came broken in half. It doesn't look great but it lost none of its function. I would buy this over and over again in figure set ups without a single concern.

water cleared up in a matter of hours. Magic

These are great! I have seen some people say that they COMPLETELY break down into small particles or are a threat to ruin aquarium equipment, this has not been the case for me. Of course overtime there will be pieces that break off (as it is ceramic) but they fall right to the bottom and can be siphoned out easily. I have had 2 "gallons" worth in the "chaeto" section of my sump of my 140 gallon reef tank for over 2 years. My ammonia, nitrate and nitrite is 0 and has never raised above 0 on any tests. I do perform weekly 10% water changes religiously and do only have 9 medium-large size fish in my system but I feed like crazy both the corals and my fish. Obviously they work in conversion of Ammonia. I can't sit here and say I'm a marine biologist and blast the product but from a long time reefer with long time perfect parameters I can tell you these work well. Add these while taking the time to maintain your tank with filter pad/water changes and you can run a successful aquarium.

tenia dudas al comprar por que vi que llegaban rotas pero ya mejoraron el empaque por que venia en una caja que dentro tenia otra caja y dentro de esta venia el producto con su empaque original, bien protegida excelente servicio y ya esta funcionando en mi acuario

Great product. Must for marine aquarium . I have seen many videos of abroad using it