MarinePure 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!

water cleared up in a matter of hours. Magic

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

Have a heavily overstocked aquarium with two of these. Never had any problems with water quality. Fantastic product, bit expensive though.

I can't speak highly enough of these bio blocks. I already had one for my 150 gallon reef that has been in there for nearly 9 months with no issues. I ordered two more since I expanded the system to 270 (added frag tank volume with little-no live rock) gallons total and I can't wait to see how three perform. Please, for the love of God, don't pay attention to these reviews saying it crashed their tank or gave them issues. Yes, it's brittle because it's so porous so you have to be careful. Yes, you NEED to rinse it THOROUGHLY! I rinsed all of mine with RO/DI water in a 5 gallon bucket several times before placing them in the tank and never had any issues or saw any sort of cycle.