Why Is My Pool Green? Causes and How to Fix It
A pool turns green when algae grows faster than the chlorine can kill it. Common causes are low free chlorine, high pH, too much stabiliser, short pump running times, a dirty filter, heavy rain, and leaves or debris left in the water. The fix is to clear debris, balance the water, shock the pool, run and clean the filter, and vacuum out the dead algae.
Common causes
Low chlorine after a hot week; pH drifting high so chlorine stops working well; stabiliser built up from stabilised chlorine; pump timers set too short; dirty filters; storms diluting the water.
How to fix it
Remove debris, test and correct pH, shock with a strong chlorine dose, brush everything, run the filter continuously and clean it often, then vacuum dead algae — to waste if there's a lot of it.
When to call a professional
If you can't see the bottom, if the water stays green after a shock, or if the filter keeps clogging, a professional recovery is usually faster and cheaper than repeated DIY treatments.
Need a hand?
Call Sam on 0492 000 032 for a free quote anywhere in Sydney.