Scottsdale Pool Acid Wash Pool turned green: chemicals, or a drain?
A green pool in Scottsdale is nearly always the same sequence: the pump stopped or the chlorine ran out, and it was summer. After that, a few days of Scottsdale heat and sun finish the job.
The useful question is not why. It is what happens after the water clears.
First, the test that decides the cost
Look for the main drain.
- Visible, even vaguely → the algae is in the water, not the surface. That calls for balanced chemistry, a shock, the filter running around the clock, and a brushing every day. Two to five days.
- Invisible, opaque green → long enough for algae to root into the surface. Clearing the water will show staining that chemicals will not lift.
- Black or swamp-smelling → months. Drain and clean, and possibly more.
Then, the question most companies skip
What is your pool surfaced in?
On plaster, a stained surface after a long green period has a straightforward answer: an acid wash removes the stained layer, at $400 to $800, assuming the plaster has washes left in it.
On pebble or exposed aggregate, which is a large share of pools in North Scottsdale and Paradise Valley, that answer is wrong. An aggressive acid wash attacks the cement matrix holding the stones, leaving a rougher surface and loosening pebbles. The right route there is a thorough drain and clean at $200 to $450, targeted stain chemistry, and blasting for any calcium. The pebble finish page has the detail.
Anyone quoting you an acid wash on a green pool without asking what the surface is has not done the first step of the job.
Why they go green so fast here
Heat accelerates algae growth, and a Valley pool runs warm May through September. Sun destroys unstabilised chlorine within hours. Monsoon storms from mid-June through September blow dust and organic debris into the water in quantity, and organics consume chlorine, which is why a pool that was holding fine goes under on a storm night. And absence: second homes, listings, and rentals between tenants.
What it costs
| Situation | What it needs | Price |
|---|---|---|
| Bottom visible | Chemicals and filtration | Your chemicals |
| Opaque, surface sound | Drain and clean | $200 to $450 |
| Green with light staining | Green pool cleanup | $250 to $600 |
| Green, plaster stained | Acid wash | $400 to $800 |
| Green, pebble finish | Drain and clean plus blasting | $200 to $500+ |
| Large or luxury pool | Large job | $700 to $1,200+ |
From the pricing page; the cost calculator prices yours.
An empty pool is a hazard
Anyone draining their own pool should refill it promptly rather than let the shell sit. In summer sun an exposed shell heats enormously and plaster can craze within hours, and there are rules about where the water may legally go. See drained and now cracked.
Get a quote
A photo from the deck, plus one close enough to show whether the surface has individual stones in it. We cover Scottsdale, North Scottsdale, South Scottsdale, Paradise Valley, Fountain Hills, Cave Creek, and Tempe.
Frequently Asked Questions
How fast can a Scottsdale pool go green?
In July, two or three days once the pump stops or the chlorine runs out. Heat drives algae growth hard and this much sun destroys unstabilised chlorine within hours.
Should I try chemicals first?
Yes, if you can still see the bottom. From there, shock and continuous filtration usually win, and that is far cheaper than any drain or wash. If the water is opaque, the surface underneath is usually stained and chemicals will reveal that rather than fix it.
What does a green pool cleanup cost?
A drain and clean runs $250 to $600. If the plaster is stained underneath, a full acid wash is $400 to $800, though only on a plaster finish. On a pebble pool the answer is a drain and clean plus blasting where needed, not an acid strip.
The house is vacant. Does that change anything?
Only the timeline, and usually for the worse. Vacant pools are found late, and the cost tracks how long it sat rather than how bad it looks now. If you manage the property, a photograph every couple of weeks is the cheapest insurance there is.