Introduction to the Pool Blog-Pool Algae Control

I’m Jeff Caffery, Certified Pool/Spa Operator by the National Swimming Pool Foundation with decades of experience in swimming pool service and maintenance in the Lafayette, LA area. With experience beginning in the late 80s, I am owner/operator of Caffery Pool Services, L.L.C., and I’d just like to take a moment to introduce you to my new pool blog!


Here I will discuss topics of interest with respect to swimming pool maintenance. I’ve maintained some of the largest semi-public pools and too many backyard pools to count in this area over the years and currently maintain a weekly pool cleaning route. While I can never stop learning, I find pools fascinating and I have some insights that may be of interest to those wanting to know more about pools. I also encourage you to contact me if you have any questions about pool maintenance that you would like to discuss.

I’ll start by touching on algae because it’s more of a problem now with the warmer water temperatures. Algae is a plant, plain and simple. Really simple, in fact, because it only consists of a single plant cell. It’s the simplest plant form around and is very adept at growing in pools. It colonizes water by cell division and spreads extremely quickly in the summer months if controlling it is not fairly well understood. There are several methods of algae control, but I’ll touch on my favorite which is a multi-part system consisting of circulation, filtration, chlorination, pH control, basic pool housekeeping, use of an algaecide, and brushing. Algae does not like any of the above listed items and with a breakdown of only one of these strategies, algae can gain a foothold.

Circulation:

During these warm months, keeping the water moving with the filter running at least during all daylight hours really helps because stagnant water allows algae to grow on the walls and floor. Daylight hours are especially conducive to algae growth because algae is a plant and needs sunlight to photosynthesize and grow. You can’t keep it from the light, but you can make it harder for it to grow while it’s being nourished by the sun.

Chlorine:

Keep the free chlorine level as constant as possible in the normal range of 1-5 ppm. Letting it fall below 1 ppm for any length of time is a breakdown of the system, and algae WILL start growing.

pH:

pH is a measure of how acidic or basic a substance is. Keeping the pool water pH in the ideal range of 7.4 to 7.6 not only helps keep the water from irritating one’s eyes and nasal passages, but it also keeps the chlorine from being ineffective. You see, with the pH much above 7.8, chlorine in the normal range is largely ineffective on contaminants in the water. Not only will it become ineffective against algae in that circumstance, but it will also allow disease-causing microorganisms to flourish! That’s a point I often see lost in many articles written on pool care.

Housekeeping:

Keep the pool as free as possible of organic debris such as dirt and leaves as this taxes the pool’s free chlorine residual and creates small areas of stagnant water beneath debris piles. Less organic material in the water means your chlorine is available to work on those little algae cells that enter the pool all of the time.

Algaecides:

Use a maintenance dose of a good metal-free algaecide once every single week without fail, and this will act as an algae preventative. Your chlorine consumption will be reduced, and now every time it rains, your pool will not start to turn green. I say metal-free because algaecides with metals like copper and silver will work against algae, but they can also stain the pool when used in conjunction with an oxidizer such as chlorine, especially when you shock the pool.

Brushing:

Algae on pool surfaces forms a slime layer on its surface, making it resistant to the effects of chlorine and algaecides. Occasionally brushing the pool helps by removing the surface slime on black algae and dislodges mustard and other types altogether. Brushing loosens any algae colonies attached to pool surfaces where they can grow more protected from what’s in the water to kill them and puts them in suspension where the chlorine and algaecide can more effectively act on them. The correct type of robot sweeps and brushes the pool for you and can also help with the debris.

A pool kept in the above manner will be ready for the algae that enters the pool normally every day from wind, rain, and other sources and will usually not suffer a bloom of green, yellow, mustard, red, or pink algae after a rain or otherwise. I say “usually” because there are other less- common algae growth contributors that need to be looked at if the above limiters are in place and algae blooms are still present. You can contact me for a detailed assessment.

If you found this helpful, please take a moment and like my company on Facebook to keep up with more information on pool/water health.

Thanks for reading!

Jeff Caffery

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