
Seachem Prime
Seachem Prime – Complete & Highly Concentrated Water Conditioner
Prime is a complete and highly concentrated water conditioner suitable for both freshwater and marine aquariums. It removes chlorine and chloramine while also detoxifying ammonia, nitrite, and nitrate. The formula is completely non-acidic and therefore has no effect on your aquarium's pH.
Why choose Seachem Prime?
- Highly concentrated: A small dose treats a large volume of water, making Prime extremely economical to use.
- Complete protection: Removes chlorine and chloramine, binds heavy metals, and temporarily detoxifies ammonia, nitrite, and nitrate.
- Safe for biological filtration: Does not interfere with the growth of beneficial nitrifying bacteria.
- pH neutral: Has no measurable effect on pH.
Advanced support for biological filtration
Prime is especially useful during the cycling phase of a new aquarium, as it immediately reduces the toxicity of ammonia and nitrite. It contains a unique binding agent that temporarily converts ammonia, nitrite, and nitrate into a non-toxic form.
Prime also detoxifies heavy metals that may be present in normal concentrations in tap water. Use Prime when setting up a new aquarium and whenever adding or replacing water.
- Add Prime to new water before introducing it to the aquarium whenever possible. If dosing directly into the aquarium, calculate the dosage based on the total aquarium volume.
- Standard dosage: Use 1 full cap (5 ml) for every 200 liters (approximately 53 US gallons) of new water.
- Tip for smaller volumes: Each thread inside the cap measures approximately 1 ml.
- High chloramine levels: A double dose can safely be used.
- Ammonia or nitrite emergency: If ammonia or nitrite exceeds 2 ppm, up to five times the standard dose may safely be used to protect your fish.
- High temperatures (> 30 °C / 86 °F): If temperatures are high and chlorine or ammonia levels are low, half the normal dose is sufficient.
Important information about water testing
After dosing Prime, some ammonia test kits may temporarily produce misleading readings. For the most reliable results, wait approximately 24 hours before testing the water.
- Odor & appearance: Prime naturally has a strong sulfur- or garlic-like smell. Small black particles or specks may also appear at the bottom of the bottle over time. This is completely normal, has been thoroughly tested by Seachem, and does not affect the product's safety or performance.
- Unlimited shelf life: When stored properly in a tightly sealed bottle, Prime has no expiration date and remains effective indefinitely.
Perfect to combine with
- Seachem Stability: Ideal when introducing new fish to help establish and strengthen a healthy bacterial colony.
- Seachem Purigen: Seachem Prime and Seachem Purigen are completely safe to use together. Prime immediately detoxifies harmful compounds after dosing, while Purigen removes dissolved organic waste, helping maintain consistently excellent water quality.
Available sizes
Seachem Prime is available in convenient 100 ml, 250 ml, and 500 ml bottles.












