Description
AquaZen CO2 Tablets — Simple Daily CO2 Supplementation for Planted Freshwater Aquariums
AquaZen CO2 Tablets offer the most accessible entry point into CO2 supplementation for freshwater planted aquariums — 100 effervescent tablets that deliver a timed-release source of CO2 gas directly into the aquarium water with each daily dose. AquaZen CO2 Tablets support plant photosynthesis and healthy growth without a regulator, canister, diffuser, or any additional equipment. Simply drop one tablet into the aquarium each day and let it work. AquaZen CO2 Tablets dissolve within a few hours of placement — do not be alarmed by this. The tablets are designed to deliver a full day’s worth of CO2 into the aquarium environment quickly rather than dissolving slowly over 24 hours. The CO2 released supports plant growth throughout the day, helps stabilize pH, and actively reduces the conditions that allow nuisance algae to thrive.
Key Features of AquaZen CO2 Tablets
- No equipment required — no regulator, canister, diffuser, or tubing; simply drop one tablet into the aquarium daily
- Timed-release CO2 delivery — each tablet releases a full day’s CO2 supply into the aquarium water column
- Supports plant photosynthesis — CO2 is the primary carbon source plants need for healthy growth alongside light and fertilization
- Helps stabilize pH — CO2 dissolution in water produces carbonic acid which gently buffers pH fluctuations common in planted tanks
- Fights nuisance algae — consistent CO2 supplementation supports faster plant growth that outcompetes algae for nutrients and light
- Simple dosing — one tablet per 8 gallons of water per day
- 100 tablets per bottle — one bottle lasts a 10-gallon tank up to 100 days
- Freshwater use only
Why CO2 Matters for Planted Aquariums
CO2 is the primary carbon source that aquatic plants use during photosynthesis to convert light energy into growth. In low-tech tanks, plants rely on CO2 produced naturally from fish respiration and organic decomposition — often insufficient for medium to heavily planted aquariums under moderate to high lighting. AquaZen CO2 Tablets bridge this gap without the expense or complexity of pressurized CO2 systems, making them the ideal choice for hobbyists who want to improve plant growth and reduce algae in low-tech and medium-tech planted setups.
Dosing Guide
| Dose | 1 tablet per 8 gallons of water per day |
| 10-gallon tank | 1–2 tablets per day — 1 bottle lasts approximately 100 days |
| 20-gallon tank | 2–3 tablets per day — 1 bottle lasts approximately 40–50 days |
| Placement | Drop tablet directly into aquarium water in an area with gentle flow |
| Frequency | Once daily — best added at the beginning of the photoperiod |
What to Expect After Adding a Tablet
AquaZen CO2 Tablets dissolve and release CO2 within a few hours of being dropped into the aquarium. This rapid dissolution is intentional — the tablets are engineered to release a full day’s worth of CO2 quickly into the water column where it becomes available to plants immediately. Do not mistake rapid dissolution for reduced effectiveness. After the tablet dissolves, the released CO2 remains dissolved in the water column and is actively used by aquarium plants throughout the day.
AquaZen CO2 Tablets vs. Pressurized CO2 — Which Is Right for You?
AquaZen CO2 Tablets are the ideal choice for:
- Low-tech planted tanks without high-output lighting
- Medium planted tanks that need a CO2 boost without full system investment
- Hobbyists new to planted tanks who want to try CO2 supplementation before committing to pressurized equipment
- Small tanks where a pressurized CO2 system is cost-prohibitive relative to tank size
For aquarists running high-tech planted tanks with CO2-demanding carpet plants such as Dwarf Baby Tears (HC Cuba) or high-light stem plants like Rotala Wallichii, pressurized CO2 injection is recommended for consistent results. AquaZen CO2 Tablets provide supplemental benefit in these setups but are not a substitute for pressurized CO2 in demanding high-tech aquascapes.
Technical Specifications
| Brand | AquaZen |
| Model | AN-07 |
| Contents | 100 tablets per bottle |
| Dose | 1 tablet per 8 gallons per day |
| Bottle Duration | Up to 100 days for a 10-gallon tank |
| Water Type | Freshwater only |
| UPC | 858120005203 |
| SKU | AN-07 |
| Price | $17.00 |
For more on CO2 supplementation in planted aquariums, visit the JBJ Aquariums website or browse our full selection of aquatic plants at Quinn’s Fins.
