Ista External Co2 Reactor

Ista External Co2 Reactor

Ista External Co2 Reactor is an external CO2 reactor diffuser for planted aquariums. It dissolves injected CO2 fully into the water so very little gas is wasted. It suits aquascapers and planted-tank keepers in South Africa who run pressurised CO2 and want to get the most from every bubble.

Standard ceramic plate diffusers release fine bubbles into the tank, and many of these rise and escape at the water surface before they dissolve. The ISTA reactor works differently. It sits outside the aquarium on your filter line and mixes CO2 into the flowing water until it is fully dissolved. The CO2-rich water then returns to the tank, where it supports healthy, vibrant plant growth.

Key Benefits

• Efficient CO2 use: The reactor is designed to dissolve CO2 thoroughly into the water, so less gas is lost compared with surface-escaping bubbles from plate diffusers.
• Patented impeller: An internal impeller repeatedly breaks CO2 bubbles down into smaller and smaller bubbles until they are fully dissolved.
• Prevents gas build-up: The design stops CO2 gas from collecting at the top of the reactor chamber, which helps dissolution stay consistent.
• No electricity needed: The reactor runs on the water flow from your existing filter, so it needs no extra power source, cable or plug.
• Compact external design: The streamlined body mounts outside the tank, which saves space inside the aquarium and keeps your aquascape uncluttered.
• Durable build: The housing resists acid and impacts, making it a long-lasting part of your CO2 system.
• Low maintenance: It is easy to clean and maintain, so it keeps running smoothly over time.

How to Use

Fit the reactor externally on your filter's hose line so that filter water flows through it. Connect your CO2 supply line to the reactor's CO2 inlet. As water passes through, the impeller mixes the incoming CO2 until it dissolves, and the treated water carries on into the aquarium. Clean the unit periodically to keep flow and performance at their best.

Suitable For

• Planted freshwater aquariums and aquascapes using injected CO2
• Hobbyists replacing an in-tank ceramic plate diffuser to cut CO2 wastage
• Setups where you want CO2 equipment kept out of sight and outside the display

Compatibility

• Filter hoses: 12/16 mm (0.47"/0.63") inner/outer diameter
• CO2 tubing: 4/6 mm (0.16"/0.24") inner/outer diameter
• Powered by your filter's water flow, so it works alongside an external filter running on compatible hosing

Specifications

• Brand: ISTA
• Type: External CO2 reactor diffuser
• Dissolution method: Patented bubble-breaking impeller
• Hose size: 12/16 mm (0.47"/0.63")
• CO2 tube size: 4/6 mm (0.16"/0.24")
• Power: None required, operates on filter flow
• Construction: Acid-resistant and impact-resistant

Frequently Asked Questions

Will the reactor keep working during load shedding?
The reactor itself uses no electricity, but it relies on your filter's water flow. If your filter stops during a power cut, water stops moving through the reactor and CO2 will not be dissolved until flow resumes.

What hose size does my filter need to use this reactor?
The reactor is made for 12/16 mm (0.47"/0.63") filter hoses. Check your filter's hose diameter before buying.

Which CO2 tubing connects to it?
It is compatible with standard 4/6 mm (0.16"/0.24") CO2 tubing, the size commonly used with CO2 regulators and bubble counters.

How is it better than a ceramic plate diffuser?
With a plate diffuser, many bubbles reach the surface and escape before dissolving. This reactor uses a patented impeller to break bubbles down until they are fully dissolved, and it prevents gas from gathering at the top, so far less CO2 is wasted.

Will it be visible in my aquascape?
No. It mounts externally on the filter line, so nothing sits inside the tank and your layout stays clean.

Is it difficult to maintain?
No. It is designed to be easy to clean and maintain, and its acid- and impact-resistant body is built for long-term use.

When can I expect delivery?

• Gauteng (Jhb/Pta) - 1-3 working days
• Nationwide (Cpt/Dbn+) - 2-5 working days
• Outlying Areas - 3-7 working days

All orders are sent via Economy Road, typically through Fastway or Internet Express Couriers*. Estimated timeframes are not guaranteed. Once the order is collected by the courier, we have no control over third-party logistics and cannot make any time promises.

If you prefer a faster 🚀 shipping option, we also offer The Courier Guy during checkout in the dropdown selection. Please note that this option is not free, and you must choose it to use it. Please pay careful attention to the cutoff times and delivery timeframe for these options during checkout.

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Delivery times to lockers and pickup locations typically range from 2–7 working days, depending on your location.*

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Collection timeframes:

• Bob Box: Collect within 2 days of receiving your collection notification.
• PUDO Lockers: Collect within 36 hours of receiving your collection PIN or SMS notification.

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