We all come to a point as pool owners where we need to consider draining our water.  In fact, it is recommended that an entire swimming pool gets drained every five years.  This is because certain levels in the water get too high.  These are levels that cannot be adjusted chemically.  Old water makes the chemicals less efficient and can cause calcium build up and even an algae problem that we just cannot seem to get rid of.  Here are some reasons to drain your swimming pool.

High Total Dissolved Solids

High total dissolved solids (TDS) can make our chemicals less efficient.  You see, anything we add to our swimming pool water over the years can only break down to a certain molecular level.  This means something is always left behind.  These are called dissolved solids.  The measure of such solids constitutes TDS.  The reason the chemicals are less efficient is because they actually exhaust some of their efficiency while scrambling for room to dissolve.  Think of too many cars trying to get on the freeway at rush hour.  Anything measuring over 2,500 ppm (parts per million) is considered a high TDS.  Anything over 5,000 and the pool should be shut down.  

Salt pools are a little different.  To determine your TDS level you would check the TDS and the salt.  You would then subtract the salt from the TDS reading and that is your actual TDS.  Typically salt water pools need to be drained less often.  It is closer to 7 years.

High Salt

In my years in the swimming pool industry I have had hundreds of customers who have ended up with too high of a salt level.  This not only makes the water more corrosive than it should be, but can cause many salt systems to stop producing.  The number one reason I see high salt is because the swimming pool owner added salt simply because the system said “low salt”.  Sometimes this is the actual case and the salt is low.  A dirty salt cell, however, can often throw the “low salt” warning, even if the salinity is ok.  A bad board can also give an inaccurate salt reading.  I highly recommend taking your water into someplace that has a digital salt reader, such as your local swimming pool store, for an accurate salt level reading before ever adding salt.  

High Cyanuric

Cyanuric acid is also known as “conditioner or stabilizer”.  This is because it helps to stabilize the chlorine by acting as a sunscreen of sorts to protect your sanitizer from burning off prematurely.  The right range, which is 30-50  ppm for a traditionally chlorine pool and 50-60 ppm for a salt pool, is needed.  While these are the ideal ranges, it is said anything under 100 ppm is still ok.  Once we exceed that level, the chlorine has to work harder and is less efficient.  To what degree the sanitizer is less efficient cannot be measured because all we show are chlorine levels when we test.  Not the efficiency.  This can lead to unsafe swimming conditions.  It is suggested that swimming pools with high cyanuric acid keep their chlorine higher for this reason.

High Calcium

A lot of us have “hard water” coming out of the tap depending on where we live.  This means the calcium is high to begin with.  Ideally, we want our calcium levels to be between 200-400 ppm.  Too high of a calcium level can lead to scaling and build up.  Too little and the pool water will try to leach it out of your swimming pool’s surface causing potential damage.  Always test your source water first if you are draining for high calcium reasons.  No sense refilling with more water already over the level.

Algae Blooms

This is another common reason people want to sometimes entertain the idea of draining the swimming pool.  Should you drain or try to clean it?  It depends on a few factors.  If the water needed to be drained anyway for one of the aforementioned reasons, a drain may be a good idea.  If the algae is so bad it has caused staining on the swimming pool walls then you will need a chlorine wash or an acid wash.  Both which require draining.  If you will spend more on chemicals than it will cost to drain your swimming pool then you may want to consider draining.  In some places it is illegal to drain water with algae so make sure to check.  You may have to treat it before you drain.

A good algae regime CAN save most pools with an algae bloom.  These regimes involve brushing the pool walls and floor,pairing an algaecide with superchlorination, running the pump 24 hours and then cleaning the filter.  Some people utilize a flocculant, which will clump the algae into piles which can be vacuumed up and then expelled with a filter clean.  Check out our blog on a good algae treatment.

A few other common ways we get algae are low chlorine, old water, unbalanced water, a dirty filter and the number one cause is not circulating the water for the proper amount of time.  Many people are apprehensive about running their swimming pool pump due to the high costs.  This is true if you have an old fashioned single speed pool pump.  The newer technology of an energy efficient, variable speed speed pool pump will save you a fortune on your electric bill.  You run them longer on a lower speed which makes the water beautiful, clear and most importantly, safe.

Think you can’t afford a variable speed pump?  Think again!  You can get a name brand, American made Black & Decker variable speed pool pump for about half of what you would pay at a local pool store.  They even come with an unprecedented FIVE year warranty and are easy to install and operate.  Tired of algae and high electric bills?  Check them out here.

See you poolside!