PolypLab Genesis Rock Pack | 4 Ceramic Bio-Media Blocks for Reef Tanks

The PolypLab Genesis Rock Pack is a 4-pack of high-fired ceramic bio-media blocks engineered to host massive populations of beneficial bacteria in saltwater reef aquariums. Each 4 × 4 × 7/8 in block is sintered from a porous ceramic compound that supports both aerobic (nitrifying) bacteria on the outside and anaerobic (nitrate-reducing) bacteria deep in the core — in a single piece of media that lasts for years. Drop them into your sump, refugium, sand bed, or aquascape and let them work. Pair with the standalone PolypLab Genesis Bacterial Blend to seed the blocks fast, or browse more reef essentials in our Saltwater Collection.

Why This Pack

• 4 Genesis Rock blocks — enough surface area for medium-to-large reef systems straight out of the box.
• 23,000+ sq ft of bacterial surface area per block — one of the densest bio-media designs on the market.
• 100% high-fired ceramic — fired at 600°+, will not break down or release silicates over time.
• Aerobic + anaerobic in one block — outer surface processes ammonia and nitrite while the oxygen-starved interior reduces nitrate.
• Versatile placement — works in sumps, refugiums, deep sand beds, or hidden in your aquascape.
• Lasts for years — ceramic substrate does not degrade under normal reef conditions, so you set it and forget it.

How to Use

Initial seeding: Place the blocks in a clean container, cover with aquarium water, and dose your favorite saltwater bacteria culture (we recommend PolypLab Genesis Bacterial Blend). Soak for at least 12 hours, then transfer the blocks into your tank or sump.

Placement options:

• Anaerobic (nitrate reduction): Place blocks in a low-flow, low-oxygen area — under sand, deep in rockwork, or a quiet sump chamber.
• Aerobic + anaerobic (general filtration): Place in a medium-flow zone of the sump or display so the outer surface stays oxygenated while the core remains low-oxygen.
• Spread the load: Distribute the four blocks across both flow zones for balanced biological filtration.

Maintenance: Genesis Rock requires no replacement under normal use. Continue dosing reef bacteria as part of your regular routine to keep the bio-media saturated with active culture.

Specifications

Recommended Pairings

• PolypLab Genesis Bacterial Blend 50mL — the bacteria culture engineered to seed these exact blocks.
• PolypLab Genesis Rock Booster Set — smaller starter kit with 2 blocks plus bacteria.
• Brightwell MicroBacter7 — complementary nitrifying bacteria for ongoing biofilter support.
• Premium Salt Mixes — mix fresh saltwater for soaking the blocks during initial seeding.
• Water Test Kits — track ammonia, nitrite, and nitrate as the bacteria establish.

FAQ

Does the Pack include bacteria?
No — the Rock Pack is just the four ceramic blocks. Pick up a bottle of PolypLab Genesis Bacterial Blend separately, or grab the Genesis Rock Booster Set if you want a smaller bundle that includes bacteria.

What size tank is this Pack appropriate for?
Four blocks is well-suited to medium-to-large reef systems. Larger tanks can use multiple packs distributed across sump and display zones; nano reefs may only need one or two blocks at a time.

Where exactly should I put the blocks?
For maximum nitrate reduction, place them in low-flow, low-oxygen spots — deep in rockwork, under the sand, or in a quiet sump chamber. For balanced aerobic + anaerobic filtration, put them in medium-flow areas. Spreading the four blocks across both zones gives you the best of both.

Do the blocks ever need to be replaced?
No. The high-fired ceramic structure does not break down. As long as bacteria are dosed and the blocks are not damaged, they will keep providing surface area indefinitely.

Is this safe for fish, corals, and inverts?
Yes. The ceramic is inert and reef-safe. No livestock impact when used as directed.