Archive for June, 2011

Hazy, Hot and Humid!

Bob Russell | June 1, 2011 in Pool,Pool chemicals,Pool Service,Sanitizers | Comments (0)

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Sanitization Basics:
You should know these two concepts:
1) Chlorine demand
2) The “Petri Dish”

Chlorine counts can drop dramatically during very heavy bather use.

Chlorine Demand:
When I teach new pool owners about sanitization, I look to make the complex simple. The chemistry behind sanitization is complex. Understanding a principle like “chlorine demand” is easier than trying to understand the science behind it (although understanding the science is helpful if you’re in the pool business).
Chlorine demand is self descriptive. How can you recognize chlorine demand increases? Here are a few things a pool owner should watch for:
1) Increased bather load (number of swimmers)- swimmers (and pets!)  introduce things like ammonia into a pool which complicates chlorination and increases chlorine demand..
2) Water Temperature- high temperatures increase chlorine demand.
3) Sunlight- UV causes established chlorine counts in a pool to deteriorate. To minimize the effects of sunlight on pool sanitizer, “Chlorine Stabilizer” is added (also known as Cyanuric Acid).
4) Wind and Rain- Both introduce contaminants into pool water. Whether wind-borne pollen and debris or waterborne pollutants, both interfere with chlorine effectiveness or just use it up.
This past weekend, many pool owners turned on their heaters, the weather was hot and humid, the pools were used- a LOT; and we had some storms. It was a weekend of very high chlorine demand.
This is why many pools get algae shortly after Memorial Day weekend- chlorine settings that could handle a chilly, unused pool were not adequate to handle a warm and well-used pool.
Think about chlorine demand and you’ll anticipate these things and save yourself a lot of problems.

Pools on the coast have unique chlorine demand challenges:

The Petri Dish:
High School Biology taught me this principle: Introduce animal or plant life into a sterile environment with food and you have exponential growth. This is how you should look at your pool. What prevents the growth of things like: plant life (e.g. algae), Bacteria (e.g. E-Coli) or Parasites (e.g. Cryptosporidium)?
A: Your sanitizer does.
Example: When chlorine levels are at zero, one algae spore can turn a pool green (what is called an “algae bloom”) in about 36 hours.
Using these two principles will help you anticipate changes and prevent problems.
Enjoy the pool!