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Seachem Prime

It is the complete and concentrated conditioner for both fresh and salt water and removes chlorine, chloramine and ammonia. No other product is required to make new water safe. Use at start-up and whenever adding or replacing water. Use during tank cycling to alleviate ammonia/nitrite toxicity.


  • Converts ammonia into a safe, non-toxic form that is readily removed by the tank’s biofilter.
  • Detoxifies nitrite and nitrate, allowing the biofilter to more efficiently remove them.
  • Detoxifies any heavy metals found in the tap water at typical concentration levels.
  • Promotes the production and regeneration of the natural slime coat rather than relying on artificial or non-native slime compounds.
  • Is non-acidic and will not impact pH.
  • Will not overactivate skimmers.

Prime works by removing chlorine from the water and then binds with ammonia until it can be consumed by your biological filtration (chloramine minus chlorine = ammonia). The bond is not reversible and ammonia is still available for your bacteria to consume but not available to harm your fish. Prime will not halt your cycling process. (Most other dechlorinators remove chlorine but leave your tank full of toxic ammonia)

Why Prime?

Nearly all companies manufacture a product that removes chlorine. None of those, however, can compare in quality, concentration, or effectiveness to Seachem’s flagship product: Prime® is the second most concentrated dechlorinator on the market after our own aquavitro alpha™. A single 100 mL bottle will treat 1000 US gallons of tap water. Prime® will remove both chlorine and chloramines from municipal water supplies.

Prime® also contains a binder which renders ammonia, nitrite, and nitrate non-toxic. It is very important to understand how those two functions work together. All dechlorinators operate through a chemical process known as reduction. In this process, toxic dissolved chlorine gas (Cl2) is converted into non-toxic chloride ions (Cl-). The reduction process also breaks the bonds between chlorine and nitrogen atoms in the chloramine molecule (NH2Cl), freeing the chlorine atoms and replacing them with hydrogen (H) to create ammonia (NH3).

Typically, dechlorinators stop there, leaving an aquarium full of toxic ammonia! Seachem takes the necessary next step by including an ammonia binder to detoxify the ammonia produced in the reduction process.

Be very careful when purchasing water conditioners. If your municipality includes chloramines in the water supplies, a standard sodium thiosulfate dechlorinator is not enough. Prime® promotes the natural production and restoration of the slime coat rather than relying on artificial or non-native slime compounds. A further bonus for the reef hobbyist—Prime® will not overactivate protein skimmers.


Use 1 ml for each gallon of water. Measuring device included. The sulfur odor is normal. For high chloramine concentrations that are extremely high, a double dose may be used safely. To detoxify nitrate, in an emergency, you may use up to 5 times the normal dose.

100 mL treats 1000 gallons*. More than any other de-chlorinator

$2.86 ea
SeaChem Prime 50ml
$3.84 ea
SeaChem Prime 100ml
$7.79 ea
SeaChem Prime 250ml
$12.02 ea
SeaChem Prime 500ml- 17 oz
$46.41 ea
SeaChem Prime 2L, 67.6 oz
$79.24 ea
SeaChem Prime 4 L (1 gal) ($79.24 plus $4.00 Oversized Shipping)