Today’s BlogTopic:
Drain & Refresh Your Pool Water- -Why & When
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One of the most common questions that I receive is “Why should I drain my pool and when do I do it?”
That is a good question and a lot of you folks have been misinformed over the years.
So… as to why it’s so important and when it should be done..here’s MY version…
Why should you do it?
Well, bluntly put, the water in the Phoenix area is absolutely terrible. It’s very hard.. which is why most of us must use water softening & purification systems in our homes
There are several reasons why you should be draining your pool every 2-3 seasons. One of the most important is because of the TDS (total disolved solids.. also called hardness) build up in the pool water that takes place over time.
In the summertime, temperatures reach 100-120 degrees. Combined with low humidity and windy conditions the evaporation rate in your swimming pool is greatly excelerated. When water evaporates, only H2O dissipates. The TDS remains in that body of water. The pool water is continuously replenished with fresh water supply through the automatic water fill. The water coming into the pool has a TDS/HARDNESS factor. Thus a rise in TDS.
Example: Fill a quart container with water at 900ppm TDS. Evaporate 1/2 of that water from the container. You now have 1/2 quart of water with the TDS factor of 1800ppm. Fill the container back to its original level with Distilled water (0 TDS), and you will have your original quart of water at 900ppm TDS. The water that is being used to replenish pools is not 0 TDS, but may have a TDS factor as high as 900ppm.
Now..perform the same experiment as before. This time, fill the container to its original level with water having 900 ppm TDS. You now have 1 quart of water with a TDS factor of 1350ppm. This is what happens in your swimming pool.
In addition to evaporation, everything that enters the body of water: dirt, leaves, chemicals, bodies, etc….etc. EVERYTHING has a TDS/HARDNESS factor, which contributes to the overall rise of TDS in that body of water.
When the TDS level of pool water rises, subtle problems will begin to occur: calcium deposits on pool tile at the water line, brown manganese stains on pool plaster, salty taste to water, irritation to skin and eyes, etc.. As the TDS rises higher and higher, these problems amplify to a point where the pool will begin to deteriorate.
At high levels of TDS, calcium will begin to replace the plaster in gunite pools. This will expose itself as a dime sized circle on the plaster. At this point the calcium deposits at the water line will have grown to resemble a stalactite and manganese stains may be very evident.
The absolute maximum acceptable level of TDS is about 1500. I prefer to keep it less than 1200 when possible. When the TDS is extremely high, the water has a tendency to become “non reactive” to things that you’re putting in it (like acid and chlorine), which significantly increases your pool costs and can cause frequent uncontrollable green or yellow algae outbreaks.
We test your pool water for hardness (TDS) a few times per year. In the long run, refreshing your pool water will save you lots of dough and headaches too.
When should you drain it? NOW !
Here in the valley November thru March is the ideal time to drain.
The general rule of thumb is this:
1) If your pool has a cartridge filter and is not able to be backwashed regularly your pool water should be refreshed completely every 2 years.
2) If your pool has a sand or DE filter that is backwashed regularly the pool water should be drained & refreshed every 3 – 4 years.
3) ALL POOL SYSTEMS that use a SALTWATER CHLORINATION SYSTEM, regardless of the filtering system used, should be drained every 2 years.
So… there you have the long and the short of it. Scheduled draining and refreshing the water in your pool will help keep it sparkling clear and a pleasure to be in!
Later this week I’ll tell you a little about Tile Cleaning and Acid Washing… BOTH of which can be done at the same time that your pool is drained to save some ‘Pool Budget’ money..
Thanks again for checking out our blog and please feel free to call or e-mail me or your friendly, neighborhood, Pool-Guy if you have any specific questions regarding this or any other pool subject.
See you soon,
Ken