How to Fix Too Much Shock in a Swimming Pool

Untrained or improperly supervised staff can add too much chlorine to pools. There is a misconception that the more chlorine you add to a pool, the cleaner and more sanitary the pool be. Sometimes, a pool will have algae problems and shocking the pool with chlorine is recommended to solve the problem. Swimming pool water requires a balance of all the chemicals to maintain sanitary water and reduce pool maintenance. Too much chlorine will result in too much shock in a swimming pool. It is therefore vital to restore the chemical balance, particularly if there is too much chlorine in a swimming pool.

How to Fix Too Much Shock in a Swimming Pool

Purchase a swimming pool chlorine water test kit that specifically measures for free chlorine in the pool. A pool with too much shock will have high levels of free chlorine. Follow the manufacturer’s instructions to read the results of the test kit, since different kits vary.

Evacuate the pool. No swimmers should be in the pool when you treat for too much chlorine.

Turn on pool filtration pumps. Add one-half ounce of sodium thiosulfate granules per 1,000 gallons of swimming pool water directly into the center of the pool. Allow swimming pool water to circulate with the sodium thiosulfate granules in the water for about 30 minutes.

Turn off pool filtration pumps and unplug from the electrical source. Test the swimming pool water for free chlorine levels. If levels are still too high, repeat Step 3.

Remove pool filters when optimum free chlorine levels are reached. Replace with new pool filters.

Plug back in and turn pool filtration pumps back on. Test chlorine levels weekly. Carefully measure and follow manufacturer’s instructions when adding additional chlorine to the swimming pool to prevent future episodes of too much shock in swimming pool water.


Swimming pools should have a free chlorine level of around 2.0ppm for optimum PH levels. Sodium Thiosulfate is an instant chlorine neutralizer. Pools without chlorine odor are perfectly balanced without shock in the water or high chlorine levels.


Swimming water that causes burning eyes and noses, while smelling of chlorine, is actually the result of too much waste in the pool and too high a ratio of combined chlorine. Combined chlorine forms when waste is broken down in the water.