Seachem Prime 250ml

  • Model: 020042
 Sold Out 
Qty Discounts Off Price


Prime is the complete and concentrated conditioner for both fresh and salt water. Prime removes chlorine, chloramine and ammonia. Prime converts ammonia into a safe, non-toxic form that is readily removed by the tank’s biofilter. Prime may be used during tank cycling to alleviate ammonia/nitrite toxicity. Prime detoxifies nitrite and nitrate, allowing the biofilter to more efficiently remove them. It will also detoxify any heavy metals found in the tap water at typical concentration levels. Prime also promotes the production and regeneration of the natural slime coat. Prime is non-acidic and will not impact pH. Prime will not overactivate skimmers. Use at start-up and whenever adding or replacing water.

Why It's Different
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. 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 capful (5 mL) for each 200 L (50 gallons*) of new water. This removes approximately 1 mg/L ammonia, 4 mg/L chloramine, or 5 mg/L chlorine. For smaller doses, please note each cap thread is approx. 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 > 30C and chlorine or ammonia levels are low, use a half dose.

by Eric P. on 27/5/2019

Used for the first time on the 24/5/19 as of 27/5/19 nothing has died or looked sick in the tank far so good..

by James W. on 23/4/2018

I have used this product for a long time and have never had any issues with water quality.

by Alexis Dixon on 1/6/2016

quick delivery and great product. Best water conditioner there is.

by Alexis Dixon on 27/4/2016

Fast delivery. Simply the best water conditioner. My shrimp in particular don't like anything else being used. Only need tiny amount so lasts for ages.

by Douglas Hawke on 11/4/2016

IRecommend this product.

by Peter Copestake on 9/2/2015

I've not yet used this particular delivery but I have used the product in the past and it is by far the best make on the market even though there are others claiming to do mor eor less the same thing. highly recommended

Ask a question about this product
I urgently need some prime as i knocked my bottle over and lost the lot!! I seen somewhere you have a shop in exeter?? If so where?? I cant rely on postal service at moment as need tomorrow plus tight for cash so only option to find a shop. Thanks Matt


We're not open on weekends - sorry

HI, I use reverse osmosis water could prime seachem be added as well


Yes it could but what would you need prime for?

Ask your question here

Let us notify you when this product is back in stock!

Simply enter your details below and we will send you an e-mail when “Seachem Prime 250ml” is back in stock!

We will not send you any other e-mails or add you to our newsletter, you will only be e-mailed about this product!

also purchased