Do Orenda products kill or prevent Algae?

No, Orenda products do not kill anything. Only EPA-registered sanitizers like chlorine kill algae.

No, Orenda does not make any products that kill algae.

Our parent company, HASA, however, makes liquid chlorine, which does. Chlorine, bromine and EPA-registered algaecides can kill algae. Without an EPA registration number, no chemical should claim to kill or prevent algae.

Algaecide vs. Algaestat

An algaecide kills algae. An algaestat prevents algae. Both types of products need to be EPA-registered if they want to advertise such benefits. Orenda does not have any such products, and we do not make such claims.

Is PR-10,000 an algaestat?

PR-10,000 is not an algaestat, and neither are any other Orenda products. PR-10,000 improves water quality by removing phosphates, but simply removing phosphates does not kill (or starve) algae.

Removing phosphates and keeping levels below 500 ppb has shown to slow reproduction, but not prevent it. There's a big difference. An algaestat prevents reproduction, and Orenda does not make anything that should be considered an algaestat.

Orenda products only address non-living things like phosphates, metals, and non-living organics.

EPA Registration and FIFRA

Every product that claims it can kill or prevent algae must be EPA-registered (with the EPA registration number printed on the label). If no EPA registration number is printed on the label, the product may not be legal to sell. 

The Federal Insecticide, Fungicide, Rodenticide Act (FIFRA) requires any product that claims it can kill something to be EPA-registered. If not, it's illegal.

We do not make any FIFRA claims for any Orenda products, nor do we have EPA registration. If that changes in the future, we will revise our product labels accordingly.

HOCl (chlorine) is the best algaecide

Without a doubt, free chlorine is the best algaecide. Specifically Hypochlorous Acid (HOCl). According to Robert Lowry, water needs at least 0.05 ppm to effectively kill algae. In pools with cyanuric acid (CYA), the HOCl percentage is much lower than in a non-stabilized pool. We discuss this topic more here.

The more CYA you have, the more free chlorine is needed to attain the amount of HOCl in the water needed. Proper chlorination and minimal CYA is what we recommend for preventing algae.