Seachem Prime

Available in 2 liter (67.6 FL oz) or 4 liter (1.1 gallon)


  • Complete and concentrated conditioner for both fresh and saltwater
  • Removes chlorine, chloramine
  • Detoxifies ammonia, nitrite, and nitrate
  • 5X more concentrated than competing products


May be used during tank cycling to alleviate ammonia/nitrite toxicity. It contains a binder which renders ammonia, nitrite, and nitrate non-toxic, allowing the biofilter to more efficiently remove them. It will also detoxify any heavy metals found in the tap water at typical concentration levels. Use at start-up and whenever adding or replacing water. 


Use 1 capful (5 mL) for each 200 L (50 US gallons) of new water. For smaller volumes, please note each cap thread is approximately 1 mL. May be added to aquarium directly, but better if added to new water first. If adding directly to aquarium, base dose on aquarium volume. Sulfur odor is normal. For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to 5 times normal dose may be used. If temperature is greater than 30 degrees C (86 °F) and chlorine or ammonia levels are low, use a half dose.

Seachem Prime: Jug Size

  • Tashina  on Wed, Jan 12, 2019


    For the quality/price, this is the best all-purpose water conditioner available. It's extremely potent, therefore you don't have to use half a bottle when performing your weekly water changes. A 16.9 ounce bottle of this stuff lasts me at least 5-6 months (and I do large weekly water changes on a 75G tank). Seachem products are among the best in every category of aquarium keeping. Awesome product!


    Chris on Wed, Mar 23, 2019


    Many water conditioners claim to have ammonia removing properties (not true), or have additives like aloe vera and stress relieving chemicals, promote biological filtration, blah blah blah! You don't need half of that stuff! Seachem's Prime is your basic water conditioner for both fresh and salt water aquariums. It converts ammonia, nitrites and nitrates to a less toxic form so the bacteria/plants are still able to consume them so it doesn't mess up your biofilter. Removes chlorine, chloramines and other heavy metals in tap water. Promotes a natural and healthy slime coat on fish. All aquarists should use only Seachem's Prime!


    Dan on Wed, Mar 30, 2019


    It takes very little to condition my 55g freshwater tank, so though it looks expensive comparing prices ounce for ounce, it will actually last you much much longer. Prime is also good to use between water changes if you have a stressed fish or a sick fish that needs help recovering its slime coat. Finally, it is not harmful to plants or inverts! A truly trustworthy product and worth every single penny, IMHO. If you are looking for a great bargain, make the initial investment, as it will last you at least three times as long as other conditioners.