• Bacterial substrate, not a chemical scrubber — the granules give nitrate- and phosphate-reducing bacteria surface area to colonise, so nutrient export continues as long as the reactor is running.
• Dosed to your bioload — start at 50 mL per 100 L and increase gradually to a maximum of 200 mL per 100 L for heavily stocked systems.
• 100% biodegradable granules — fine granulation, optimised for maximum bacterial surface area.
• As low as 4c per litre treated — at the standard starting dose (50 mL per 100 L) this 1 L pack treats up to 2,000 L of tank water; even at the heaviest recommended dose (200 mL per 100 L) it still works out to $0.19 per litre.
• Feeds the reef, not just the skimmer cup — the bacterial biomass this process produces needs strong skimming to export it, and some of it also becomes food for corals and other filter feeders.

Start at 50 mL of NP Biograin per 100 L of aquarium water in your fluidized bed reactor. Give it time to colonise and let nitrate and phosphate respond before judging results — bacterial substrates work over days and weeks, not hours. If NO3 or PO4 stay higher than you want, increase the dose in steps, retesting between increases, up to Aqua Medic's stated maximum of 200 mL per 100 L.

Suitable for marine and reef aquariums running, or adding, a fluidized bed reactor to bring down nitrate and phosphate. Aqua Medic markets NP Biograin specifically for saltwater aquaria; we have not found manufacturer guidance confirming freshwater use.

Not suitable as a stand-alone fix without adequate skimming — the bacterial biomass it produces needs to be exported by the skimmer, or nutrient reduction stalls.

Run vigorous protein skimming alongside the reactor to export the biomass the bacteria produce — this is what actually removes the nitrogen and phosphorus from the system, rather than just converting it. Monitor NO3 and PO4 with a test kit and adjust the dose within the 50–200 mL per 100 L range accordingly. Aqua Medic does not publish a fixed replacement interval for the granules; top up or replace as the volume in the reactor visibly depletes.

Covered by your rights under Australian Consumer Law. Standard delivery applies.

How much NP Biograin do I need to start?

Begin at 50 mL per 100 L of aquarium water in your fluidized bed reactor, then reassess after your nitrate and phosphate have had time to respond.

Can I increase the dose if my nitrate and phosphate stay high?

Yes. Aqua Medic rates NP Biograin up to 200 mL per 100 L for heavier bioloads, but increase gradually and retest rather than jumping straight to the maximum.

Do I need a specific reactor to use this?

It is designed for fluidized bed reactors, such as the Aqua Medic Multi Reactor, where water flow keeps the granules suspended and gives bacteria constant contact with fresh water.

Why does my skimmer need to work harder after adding this?

The bacteria colonising the granules convert dissolved nitrate and phosphate into biomass, and that biomass needs to be exported. Vigorous skimming is how it leaves the system, rather than breaking back down into the nutrients you started with.

Is this safe for a freshwater tank?

Aqua Medic markets NP Biograin specifically for saltwater aquaria. We have not found manufacturer guidance confirming freshwater use, so treat it as a marine/reef product until Aqua Medic states otherwise.