How Often Should You Put Stress Coat in an Aquarium Tank?

The slime coating on a fish is a mucoprotein layer that protects the fish against infection and acts as a barrier against electrolyte loss from osmosis. Stressors such as being shipped in large numbers in small containers, fighting and net capture can damage the natural slime coat, leaving a fish open to disease. High ammonia levels from dead or decaying food or fish, sudden temperature fluctuations and low-oxygen/ high-carbon dioxide (CO2) levels can also damage the slime coat. Researchers discovered in the 1980s that Aloe vera could heal a fish slime coat as well as damaged fins and scrapes. Stress Coat was born.

  1. The Facts

    • Stress Coat is a water conditioner used in aquariums and ponds to perform two duties necessary for healthy fish: breaking chloramine bonds and removing heavy metals from water such as copper and zinc; and coating fish with a measure of Aloe to promote healing and improve the natural slime coat that protects fish against bacterial and fungal invasion. How often you will need to put Stress Coat in an aquarium varies with how often the fish are stressed or water is changed.

    Ingredients

    • The material safety data sheet (MSDS) for Stress Coat lists the ingredients as aloe (Aloe barbadensis/vera extract/gel), sodium thiosulfate anhydrous, and water. The solution is set at 80 percent water; you dissolve Stress Coat further by adding to aquarium or pond water. This greatly reduces the chance of any irritation from direct contact with the two active ingredients and resolves issues of overuse. The makers of Stress Coat claim you don't need to worry about putting Stress Coat into the aquarium too often; you cannot overdose the fish.

    Dose

    • Use a ratio of 2 teaspoons of Stress Coat for every 10 gallons of aquarium water. If you accidentally add more than this, do not worry. Add Stress Coat whenever you change the water, add new fish or if the fish have been stressed. Directions on the bottle say to add the full dose to the whole tank with every water change. Water changes of 20 percent once a week are recommended.

    Expert Insight

    • Experienced aquarists point out that while an "overdose" of Stress Coat is not harmful to the fish, adding the full amount of Stress Coat every week will leave a layer on the surface of the water that resembles an oil slick and does not allow CO2 bubbles to pop, which can create a foam.

    Prevention/Solution

    • When adding Stress Coat during a water change, calculate how much is needed in the amount of water being replaced, not the full amount of the tank. For example, a 20 percent change for a 10 gallon tank is 2 gallons removed and re-added. 20 percent of 2 teaspoons is .4 teaspoons; for simplicity, add 1/2 teaspoon of Stress Coat to the 2 gallons of water to be added back to the tank. Allow the water and Stress Coat to sit for a few minutes before adding to the aquarium. This ensures the dechlorinator has had time to work on the new water and avoids foaming issues associated with too much Aloe.