Marineland Diamond Blend Carbon and Zeolite

Marineland Diamond Blend mixes Black Diamond Premium Activated Carbon with zeolite in one 50-ounce container. The carbon handles dissolved organics, odor and discoloration. The zeolite absorbs ammonia directly from the water.

Freshwater only

Zeolite works in freshwater and ponds. In saltwater, the salt competes with ammonia and pushes it back off the zeolite, so this blend isn’t meant for marine tanks.

When it helps

• A new tank where ammonia spikes before bacteria settle in.
• Overstocked or heavily fed tanks between water changes.
• Ponds and stock tanks that need extra ammonia control.

Test as you go

Marineland tells you to test ammonia regularly and add the blend as needed. That matters, because zeolite fills up. Once it’s full it stops absorbing, and you won’t know unless you test.

A note on cycling

Zeolite removes the ammonia that nitrifying bacteria feed on, so heavy use during a fishless cycle can slow the cycle down. Use it as a safety net, not a replacement for a cycled filter.

How to use it

Rinse the media, fill a mesh bag loosely and place it after the mechanical stage. Swap it out once ammonia readings creep back up.

For a pond, place the bag where water flows through it, such as in the filter box, not resting on the bottom. In a hang-on aquarium filter, the bag can sit behind the cartridge. Rinse it before use to clear dust, which otherwise clouds the water for a few hours.

Related products

If you only need carbon, plain Marineland Black Diamond is the same carbon without zeolite. To speed up bacteria, Tetra SafeStart Plus adds live nitrifiers.