Green pool water is mostly associated with algae (either alive or dead) and usually happens as a result of either incorrect chemical treatment, long periods of hot weather (which results in more swimmers),incorrect filter operation or a mixture of some or all of these. Green water can also happen immediately following heavy rainfall or pool “top ups“. This is due to the changed chemical balance in the pool or, in the case of top ups, can be the result of algae in the tap water.
The good news it that it is easily treated, and, provided you follow the instructions below, your pool should be back to sparkling blue health in a short space of time.
1) Turn filter off. (Do not resume usual filtration until pool is clean / clear)
2) Remove solid debris (leaves etc.), then brush walls with broom/nylon brush.
3) Shock dose with chlorine (usually 1kg) [2kg for pools more than 60,000 ltrs] This will make sure the algae is well and truly dead. We recommend using our FastChlor as it can be sprinkled directly over the pool without the filter running. If any other type of dry chlorine is used it MUST be mixed in a bucket first & then poured around the pool or you risk bleaching the pool surface. Top up pool.
4) If cloudy/green/black, add Pool Pac (usually 1 ltr upto 60,000 ltrs) by directly broadcasting over the pool surface. DO NOT mix in a bucket first as directed on the label as this is the treatment you would use if the pool were only slightly cloudy. Leave filter off.
5) Wait until settled (can make out bottom of pool) usually with 24 hours. If the pool still looks yuk after 24hrs you will need to vacuum to waste (blind vac). This will help the remaining cloudiness/green to settle to the bottom. At this stage you may wish to add a 2nd bottle of Pool Pac as per the directions above. Test Chlorine level and add more chlorine if needed - do this after each vacuum.
6) Vacuum to waste.
7) Top up pool and repeat vacuum to waste until clear. When you think "Great - one more vacuum should do it", run on filter position for 4-5 minutes. This will clear all the dirty water sitting in the pipes. Let everything settle and give the pool its final vacuum.
8) Give filter good long backwash then rinse.
9) When clear - re-test, dose and balance water and reset filter timer.