Winter is coming… will you be ready?

Winter snowflake molting in winter

Often, winterization of pools ignores water temperature, but not the Orenda winterization program. We feel it is better to be proactive and winterize by preparing for the coldest water temperatures for your REGION. Southern California will be different than New York!

Cold water is more aggressive than warm water because of how water temperature lowers the Langelier Saturation Index (LSI). If the water is deficient in calcium (or other factors on the LSI like alkalinity and pH), that’s a problem. This means feeding the pool the calcium and alkalinity it needs to survive the winter without feeding on the pool surface, causing problems like calcite crystals, winter dust, fading liners, and etching.

Screenshot of Orenda app

Traditional pool winterization in areas that water freezes is about cleaning the water, loading it with chemicals from a winterization kit to prevent algae, maybe adding some anti-freeze, blowing the water out of the pipes to prevent freeze damage, and putting on the pool safety cover.

Winterization kits have nothing to do with the LSI – they are mainly chlorine, algaecides and a sequestering agent.  Do you really need them? Temperature slows everything down.  Sequestering and chelating agents (like our SC-1000) do not work in cold water (under 65 degrees) and stay dormant.

Instead, problems can be prevented by taking an LSI-based approach to pool winterization. This procedure addresses both the proper balance of water (LSI), and the sanitization of water to prevent it from turning green and nasty.

Test your water chemistry and input it in the Orenda app.  Then lower the water temperature on the right side of the calculator.  Figure out how you want to get the LSI on the right to be green… something between 0.00 and +0.30

Err to the high side of calcium. Find out how much calcium hardness your water will need when the temperature gets to its lowest point.  Plan for a little colder than you might expect… look at what happened to Texas in February 2021. Don’t be afraid to raise your calcium to something way higher than you would operate in the summer. 500 – 550+ ppm is great if your pool freezes and 400 ppm calcium hardness is the bare minimum in our opinion.  Keep in mind, rain and snow will get into your pool (unless you have a solid cover), and this precipitation will dilute your water.

  1. To keep the pool clean, we recommend removing phosphates with PR-10,000 before you close the pool.  When the dust settles, vacuum the pool and clean the filter.
  2. When the water is lowered below the return inlets, and the lines are blown out, purge the pool with CV-600 enzymes. If you want to add a sanitizer, feel free, but shocking is unnecessary.  Just make sure it is non-stabilized chlorine like liquid chlorine or cal hypo.

Predict the cold and prepare for it, or else your pool will suffer the consequences.  That is the proactive way to winterize a pool.