A green swimming pool is the most common emergency call we receive from Dubai villa owners between May and September. By the time the water turns visibly green, the problem has usually been building for several days — and in Dubai's summer temperatures, those several days are enough to turn a minor chemical imbalance into a full algae bloom that requires intervention beyond what pool-shop chemicals alone can fix.
Why Your Pool Goes Green
Green pool water is almost always algae, typically triggered by chlorine levels dropping below the threshold needed to kill it. In Dubai, chlorine consumption accelerates dramatically in summer: temperature degrades chlorine faster, UV exposure breaks it down, bather load consumes it, and shamal dust introduces algae-feeding nutrients. A failed salt chlorinator or a pump that trips its breaker can go unnoticed for 24 hours — which in July is long enough for algae to establish.
The Timeline: How Fast It Happens
Day 1 to 2 after chlorine drops: water looks slightly dull. Day 3 to 4: green tint develops, most noticeable in the deep end. At this stage, shock treatment can usually restore clarity within 24 to 48 hours. Day 5 to 7: visibly green throughout, walls feel slimy. Chemical treatment is still possible but takes 3 to 5 days. Day 7 plus: opaque green, cannot see the bottom. The pool typically needs draining, acid washing, and refilling — a 2 to 3 day process costing AED 1,500 to 3,000.
What to Do Right Now
Test the water properly with a titration kit, not dip strips. Run the pump continuously — not on a timer. Clean the filter before starting treatment. Brush every surface to disrupt algae biofilm. Shock with the correct dose of unstabilised chlorine calculated for your pool volume. If you cannot see the bottom, if the pool has been green for more than a week, or if you have tried shocking twice without improvement — call a professional immediately.
Prevention
The weekly service that costs AED 350 per month is cheaper than a single AED 2,500 acid wash. More importantly, it means your pool is always swim-ready. In Dubai, weekly professional service is not a luxury — it is the cheapest way to own a pool.