🐠 CerMedia MarinePure Block Bio-Filter Media: Ideal for Marine and Freshwater Aquariums, 8x8x4-Inch Review

Bought some larger and smaller stones for my reef protection. After 2-3-6 months it started to crumble, turned into mush = big cleaning. High nitrate and phosphate levels. Back to live rock and all good water chemistry.

The product dissolved in my pan and dusted all my gear. I had high hopes for this product but the large blocks just seem to fall apart. Maybe small cubes work better. I will recolonize another carrier and replace it in just 3 months.

It didn't take long to flush this unit and clear water flowed. It took about 5 minutes for the device to fully discharge. My block came in the corner without a half. This is the only reason I am not rating 5*. The dimensions of this block are perfect for my 20 gallon sump.

I have now received 3 blocks from two orders. Without them I will never have a tank again. I have 2 blocks in my 160 gallon salt water tank. I have very few rocks in my aquarium, I wanted to look at it openly and this was the best way to do it. Arrived perfect, no broken blocks! I am very satisfied with everything, will buy another one for the next tank.

Item was well packaged upon arrival. At the first contact with water, some of its parts crumbled. When I emailed the company, they responded in less than 15 minutes and explained. So I decide to keep the product to myself and be more skilled in handling it with my palms. I can't wait for it to work its magic.

I've been using this product for many years and I think it's a great product. So why rate 1 star. I just opened the product and found that 1/10th of a block is nothing but crumbs in a bag. Bought for my 3xl 900 Redsea 240 gallon sea water. Because of this, I might try a different product next time. Usually there are crumbs but this time there were so many that I was disappointed. Well, it's installed and I don't want to remove it and return it now.

I bought a large stone because I have been using MarinePure for years. I have used 3 cu ft of this in my carp pond shower and also in some freshwater setups. I ordered this for my reef tank and as expected it is a good choice for biological filtration. Due to its porous construction, it gets the job done but can't take the rough handling. My brick broke in half. It doesn't look very good, but it hasn't lost its function. I would buy this again and again in figure sets without a single issue.

Although this product is incredibly porous and theoretically of great importance - this block is incredibly crumbly even with very careful handling - on rinsing the outer layer fell off and even on the second rinse - the same it should to be placed in the slow flow zone of your sump, i.e. just before the last baffle and sponge protecting my last sump with a return pump inside. I put it on and immediately saw a bunch of granules from the block on my last sponge - it makes me nervous about my…