CerMedia MarinePure Biofilter Media Gems

High-Performance Biofilter Media for Nano Tanks!

• High Surface Area Biofilter Media
• Great for Nano Tanks
• Increase your canister filter capacity
• Country Of Origin: USA

Inert and chemically stable, MarinePure Gems are a great addition to any aquarium that needs more biofiltration. Bacteria prefer to grow on surfaces, and by adding more surface area in your aquarium, you will give more space for beneficial bacteria to grow and proliferate which can help reduce nutrients and maintenance. The Gems can be placed anywhere under water, in the sump, back chambers of an All-In-One aquarium, inside overflows, or anyplace where a decent amount of flow around the Gems would be present.

The MarinePure GEM is about ¾“ diameter part that will be the perfect biological media for canister filters, hang on the back and nano-tank systems up to 70 gallons. The GEMs have the same porosity as our popular MarinePure SPHERES. Their unique combination open flow porosity and high surface area means one box of these little beauties is packed with over 1,450 Square Feet (135 Square Meters) of accessible Surface Area. They will be the perfect solution for ammonia and nitrite elimination, and most users will also see better control in Nitrates. Please contact your favorite MarinePure dealer for more details.

Gem Size – ¾“ diameter

For Tanks up to 70 Gallons

• Open porosity
• 1,450 in² of surface area per box
• Lowers tank maintenance
• Does not create a mini-cycle
• Stable & inert
• Can be placed almost anywhere

How to use:

Rinse the gems with saltwater or RODI water to remove any dust or loose particles. Place the gems in a canister filter, HOB filter, or any other high flow place throughout your tank. It is suggested to have them placed after mechanical filtration to keep debris and detritus from clogging the gems exterior pores.

Specifications

Part size: about ¾ inch (19 mm) diameter per gem
Box weight: 90 g
Designed for: ammonia and nitrite removal, with nitrate control as a secondary benefit
System size: up to 75 gallons — about 285 litres
Where it goes: canister filters, hang-on-back filters, all-in-one back chambers, overflows, nano-tank filter systems, or anywhere underwater with reasonable flow
Water types: fresh and salt
Porosity: the same as CerMedia’s Spheres

Material: inert aluminosilicate ceramic, fired above 1000 °C. CerMedia state it will not leach anything into tank or pond water, and that it is stable in both fresh and salt water.

Surface area: over 1,450 square feet — about 135 square metres — per box. That is CerMedia’s own figure and the units are square feet. Our page has carried a bullet reading ‘1,450 in²’ alongside the correct figure in the body text; square inches would be smaller by a factor of 144 and is simply a typing error. 135 square metres in a 90 g box is the claim, and it is the reason the product exists.

On the system size. CerMedia currently publish 75 gallons for the Gems; our listing has carried 70. Use 75 — about 285 litres — and note that CerMedia’s separate FRESH GEMs pack, which includes a mesh bag, is rated for 40 gallons instead. If your filter is bigger than a nano canister, ask us about the Spheres or the Block, which are the same ceramic in a form that suits a sump.

What CerMedia do not publish for the Gems: a piece count per box, and no weight per gem. At ¾ inch a box holds a lot of them, but we are not going to put a number on it that CerMedia have not measured. CerMedia’s own VAULT container, for scale, is quoted as holding over 900 Gems — which is ten boxes of this size.

Mesh bags are a separate CerMedia product. Their small bag (4 × 6 inches, non-toxic polyester) is sized to hold 90 g of Gems, which is exactly one box — and a bag makes them far easier to lift out, rinse and put back. We do not stock the bags; any fine media bag will do the same job.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Filter media and substrates carry no manufacturing or expiry date — their working life begins on first contact with water, not on the shelf.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.