Dissolving Pool Cyanuric Acid Using A Sock


Cyanuric Acid for pools is sold in granulated form. It tends to dissolve very slowly, accumulating at the bottom of the pool or in filters. Instead, by placing the granulated acid in a sock in the pool strainer, it can dissolve relatively quickly and not build up in undesirable locations.

Undesirable Alternatives

The CYA package recommends either:
  • Pouring it directly into the strainer basket, where it is carried away into the filter to dissolve. Having the acid slowly dissolving right in the filter seems to risk harming the filter. Further, if you backwash the filter the undissolved acid is lost.
  • Sprinkling it in the pool. This results in the granules accumulating on the bottom of the pool. This is unsightly, unpleasant underfoot, and prone to removal by pool vacuums.


Instead of those choices, the best technique is to place the acid in a sock in the strainer basket. Take a clean sock, preferably a long one, and fill it halfway with cyanuric acid. Tie the sock off. Place it in the strainer basket, preferably while the pool pump is running.

Check the sock once every 1-2 days until all acid is dissolved. Use your test kit to check if the CYA level is in your preferred range.


This technique works very nicely. The acid is dissolved while in the sock, so it circulates nicely in the pool water. Granulated acid never leaves the sock. In the strainer basket it dissolves quickly since there is a high rate of flow over the granules.
Last modified on 12 Aug 2014 by AO

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