When should I drain my pool?Updated 7 months ago
While it may sound like a great idea to drain the pool, cover it up with a tarp, and call it a day, it's actually not a really good idea. It would be best to consult with the builder of your pool first if you're thinking of draining your pool for the first time.
And as a rule of thumb, if you're planning on doing maintenance on your pool (painting, repairs, and re-tiling) it is best to drain the pool at the last minute, do not leave your pool drained for extended periods of time.
If you're not going to use your pool for extended periods of time, it’s typically recommended to "close" your pool by lowering the water level just below the skimmer, properly balancing the water chemistry, and using a high-quality pool cover to keep it protected from the elements.
Dangers of Draining a Swimming Pool:
Hydrostatic Pressure:
- The greatest danger when draining a pool is hydrostatic pressure. Fancy term, right? It’s essentially the pressure exerted by groundwater around and under your pool, pushing against its walls and floor. Water is heavy, and this pressure can be significant.
- If you drain your pool without proper planning, hydrostatic pressure can cause damage:
- Concrete Pools: The pressure from water below can shift and crack the pool floor.
- Vinyl or Fiberglass Pools: Hydrostatic pressure can lift the pool floor, damaging both the floor and walls.
Solution: Some pools have “hydrostats” (hydrostatic pressure relief valves) installed in the deep end. These allow water from underneath the pool to flow in, relieving pressure. If your pool has hydrostats, never drain it without opening them.
Weight of Water Around the Pool:
- If the water table is higher than the deep end of your pool, the water in the ground around your pool will exert pressure on its walls.
- Backfilling during pool installation affects this. Older pools usually have elevated clean-outs, while newer ones have ground-level clean-outs. Be cautious when draining near your house.
If you would like to dive deeper into the reasons why you shouldn't drain your pool without help from a professional check out the full article here.