cleaning algae on pool bottom

Question
I was hired to clean the patches of algae on the bottom of my club pool. What technique should I use to clean it off?  I have tried using a copper brush, which scrapes the pool bottom.  Would a nylon brush, or chemicals work?

Answer
Hi Mike. The first thing you need to do is get the water balance tested. This can be done at either a local pool supplies store or by yourself if you have a test kit. More often than not, the cause of algae is your water balance being off and your chlorine/bromine is no longer effective. There are three main parts to water balance: Total Alkalinity, pH, and Chlorine/Bromine level. They must be corrected in that order. Provided your Alkalinity and pH are within a normal range (Total Alkalinity 80-120, pH 7.2-7.6), you should treat the algae with a chlorine shock. I strongly suggest using the strongest shock available in powder form (you probably don't want to use liquid Chlorine). If the pool has a vinyl liner, you need to brush the bottom and all sides with a nylon brush. If it is a cement pool, you can use a wire brush. After brushing all sides and the bottom of the pool, mix the powder shock in a bucket of the pool water. One pound of shock will treat 10,000 gallons of water. However, because you need to super chlorinate, you will need to put in at least one extra pound of shock. For instance, if you had a 30,000 gallon pool, you would super chlorinate with 4 pounds of shock. Keep people out of the pool for 24 hours if possible. After the shock is applied to the pool you will notice the water may turn a milky white color, or may have white particles. That white color is dead algae, and you simply must run your filter all day every day until it clears. If you want to you can use a water clarifier, which will bunch up some of the smaller particles your filter is not catching, and may speed the process. It is very important you keep an eye on your filter pressure while you kill the algae. When it gets too high, you will need to backwash, possibly as many as 2-3 times before the pool is clear. That should take care of the problem. The most important part of the process is getting your water tested at a pool supplies store. If you have a Leslies Pool Supplies in the area, I strongly suggest their service. With a little patience and money, the problem should be gone within a couple days. Good luck!