is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Stress Coat vs. Prime (Which Should You Use?)

stress coat vs prime
One of the most discussed subjects among aquarium keepers is water conditioners. Water conditioners are salt-free agents added to the water to eliminate harmful chemicals such as chlorine and compounds such as lead. To determine which water conditioner is best for your tank, let’s compare stress coat vs. prime. We will look into their efficiency, benefits, dose, and price.


Stress Coat vs. Water Conditioner – What is the Difference?

API Stress Coat Seachem Prime
Efficiency Dechlorinates tap water of harmful chemicals. Dechlorinates freshwater and saltwater. Effectively eliminate toxic chemicals and substances.
Benefits Forms a slime coat around the fish that accelerates healing, reduces tissue damage, and lessens stress on the fish Keeps the water quality high.
Dose 5 ml per 10 gallons of water 5 ml per 50 gallons of water
Price $4 – $6 per 500 ml $18.99 – $19.99 per 500 ml

Stress coat is one of the water conditioners on the market. But it has different ingredients and claims to do more than just dechlorinate water. Let’s find out the difference between a stress coat and a water conditioner.

Generally, water conditioners dechlorinate water. Aside from chlorine, it also removes nitrate, ammonia, and chloramine. It makes the water suitable for fish to inhabit.

The stress coat can also dechlorinate. It is less concentrated than a water conditioner, so you would need more dose to dechlorinate the water properly. However, it also provides the soothing effect of Aloe Vera and accelerates healing.

Seachem Prime

Seachem Prime is a well-known water conditioner among those in the hobby. It is highly effective in eliminating harmful chemicals such as chlorine and chloramine. It helps your filtration easily remove ammonia, nitrate, and nitrite too. Many aquarium keepers vouch that the Seachem Prime improves water quality and provides a healthy living environment for all fish.

API Stress Coat

Aside from acting as a water conditioner, the API Stress Coat provides the soothing effect of Aloe Vera to reduce fish stress. It also reduces tissue and muscle damage by forming a synthetic slime coat around the fish. This synthetic slime accelerates the healing of the fish.

The production of natural slime coat in a fish is usually interrupted by handling, fighting, travel, or anything that causes stress to the fish. There are stress coat users who do not use it for dechlorinating. Instead, they use it to address high levels of stress and diseases.

Comparison in Efficiency

In comparing the efficiency of each product, we must consider the dosage. For every 50 gallons of water, whether saltwater or freshwater, you will need 5 ml of Seachem Prime to get the most out of it.

It works well for water replacement and when adding new plants to the tank. For a much easier filtration, it breaks down unwanted compounds. And when you think that’s all it could do, think again because it also repairs the secretion of the natural slime coat.

On the flip side of the coin is the API Stress Coat. As stated earlier, it forms a synthetic slime coat around the fish, which lessens their stress considerably. It also works great for treating tap water. But to make it as effective in dechlorinating as the prime, you will need 5 ml for every 10 gallons of water.

If you have a particular fish that loves getting in trouble, fighting, or simply accidentally hitting at objects, then a stress coat is what you need. But if your tank issue is more on with the chemicals and optimal water parameter, you might want to use prime.

Comparison in Price

Now, let’s talk about prices. Stress Coat vs. Prime — which is the wiser buy? The API Stress Coat is a lot cheaper than Seachem Prime. However, considering the dosage, it may prove a little more costly.

The API Stress Coat can cost $4 – $6 for every 500 ml, while the Seachem Prime can cost from $18.99 – $19.99.

Let me help you with the math.

With every 500 ml of Seachem Prime, you will be able to treat 5,000 gallons of water. But with every 500 ml of API Stress Coat, you will be able to treat only 1,000 gallons of water. You need five times more API Stress Coat than Seachem Prime when dechlorinating water.

But keep in mind that a stress coat incredibly reduces stress on your fish. If not treated, stress will eventually lead to an untimely death.


Stress Coat vs. Prime are close competitors in the market. As the need for a water conditioner in a tank is more and more realized and appreciated, these products take the limelight. Both products are highly efficient at their jobs and are safe for any fish in the tank. Knowing what you now know, choose which you will use.

4.7/5 - (10 votes)