How to shock a pool correctly.

[Elgin]

Basically you add a load of chlorine.  How much will depend upon the volume of the pool and whether or no there is an issue with the pool (e.g. if you have chlorine "lock" or "block" you might need more).  When depends.  I always shock my pool at the beginning and end of the season and if there is a problem (e.g. algae growth).  Pool should be shocked after filling from empty as well.

The chlorine can be bought if granular or liquid form.  In granules it will be called Chlorine shock or "chock".  You can get it in pool shops, most ferreterias and many supermarkets.  If you buy the granular stuff it will normally say on the tub how much to use.  In liquid form you can actually use ordinary bleach (sodium hypochlorite - hipoclorito de sodio) from the supermarket (usually in the yellow bottle) However, you will need lots of it as it's only 5% concentrated.  I think Longo`s now stock it in 15%.  The liquid is cheaper but it is a bit hit and miss as to how much to use (I think I figured out that for an 85m3 pool I needed about 40 litres of 5%).  The granules are probably a little easier to use if you not sure what you are doing.

Process:

1) Turn the pool pump on

2) check the PH of your pool.  If it is not between 7.2 and 7.6  the treatment will not be as effective.  If the PH is out add PH-* or PH+ as required,  leave it with the pump running for a while and check the PH again.

3) Add the chlorine.  If using granules, mix it with water in a bucket first (max 500g per bucket of water), and then pour it all over the pool.

4) After an hour check the Chlorine level with the analyser kit, it should go dark yellow (almost brown).  If test shows no chlorine at all you have a chemical balance problem with the pool that can only be cleared by shocking with an awful lot more chlorine.

5) keep the pump running for about 24 hours checking the chlorine level now and then.  If it drops low you might have to shock again.  Also, check the pool Ph again and adjust if necessary

6) Do not put your summer cover back on the pool until the chlorine level has dropped to a reasonable level.

* Note PH- liquid from pool shops and supermarkets is hydrochloric acid usually about 10% concentrated and costs about €3.50 for 5 litres.  However, if you buy agua fuerte (salfumant) fromthe supermarket it is usually 20% concentrated hydrochloric acid and costs about €2.50 for 5 litres.

Final note these chemicals are powerful so wear old clothes when preparing / using them, if you spill them wash them off with lots of water quickly, always add powders / granules to water when mixing (not water to granules), never mix chemicals together and keep containers out of the sun.

[stean]

How do I shock my pool the right way and how often.