Borates are highly recommended for pools. Adding borate is a one-time thing. Borate does not decompose, get used up or expire. Borate is only lowered by water loss – splash out, drag out, leaks, and filter backwashing , or draining. So, you add it once, and unless you are losing a lot of water, you don’t need to add it again until you drain the pool and refill it.
Benefits of Using Borate
- Keeps the pH of the water from going up (pH buffer against rises in pH)
- Helps prevent algae (it is an algaestat, not an algaecide)
- Lowers chlorine demand (preventing algae lowers the need for chlorine)
- Helps protect HOCl (hypochlorous acid – the killing form of free chlorine) from UV destruction
- Water feels softer and silkier
- Water looks clearer and sparkles
Except for the last two points, these are not just manufacturer or sales claims but proven benefits when the concentration of borate in the water is 50 ppm. There is no published evidence in physical science for a mechanism of enhanced blue color or sparkle or for a silkier or softer feel to water. However, these anecdotal claims still persist in manufacturer’s literature, service tech observations and pool owner reports.
Pools equipped with SWG (salt water chlorine generator) or ECG (electronic chlorine generator) will benefit from a level of borate of 50 to 70 ppm, however, the US EPA and NSF do not recommend levels more than 50 ppm. More later.