TROUBLESHOOT
Green pool water
Result
A pool that keeps going green is usually not short of chlorine
This one is a technician's job
We cannot call it from here — we have narrowed it to a short list, but it takes a measurement or a look at the real thing to know.
When chlorine goes in and the pool goes green anyway, the usual cause here is cyanuric acid — stabiliser — building up. Almost every chlorine tablet carries it, and it does not evaporate. Past roughly 80–100 ppm the chlorine you add is effectively locked and stops sanitising. The only fix is to replace part of the water; adding more chlorine cannot undo it. We will not guess how much water from a web page — that needs a real measurement first.
We stop here because the next step needs an instrument, or carries a risk not worth taking on. Handing this to a technician is the correct answer to these symptoms — not a cop-out.
What to do
- 1
Bring us about 500 ml of water taken at elbow depth, or ask us to come and test at the pool.
- 2
Stop using trichlor tablets in the meantime. Liquid chlorine or calcium hypochlorite granules do the same job without adding to the build-up.
- 3
While you wait, hold pH at 7.2–7.6 and keep the pump running 8–10 hours a day so the algae does not gain more ground.
Read the full article: The water numbers to hold, and how to move them
Send us this position on LINEThe link tells us every answer you have given, so nothing has to be repeated.
STILL NEED HELP
Still not fixed?
Search the whole support centre, or talk to our team. We answer the phone and LINE in working hours, and we can come out to the pool.
Mon–Fri 08:30–17:30 ICT · LINE @jdpools