Pool turned green: can chemicals save it, or does it need draining?

A green pool in Chandler is nearly always the same sequence: the pump stopped or the chlorine ran out, and it was summer.

The useful question is not why. It is whether the water can be brought back chemically or whether the plaster underneath is already stained, because those are a bag of shock and a $300 to $800 job.

The test that decides it

Look for the main drain.

• Visible, even vaguely → the algae is in the water, not the plaster. Balance, shock, run the filter continuously, brush daily. Two to five days and it is yours again.
• Invisible, opaque green → it has been long enough for algae to root into the plaster surface. Clearing the water will show you staining that chemicals will not lift.
• Black, swamp-smelling, or with wildlife in it → months. Drain, clean, and usually acid wash.

Why it happens so fast here

Heat accelerates algae growth sharply, and a Valley pool runs warm from May to 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 pools that were holding fine go under on a storm night.

And absence. Rentals between tenants, listings, and the seasonal homes around Sun Lakes and the 55-plus communities that sit empty for the summer. A pump on a timer with nobody watching is how most green pools get that way.

Chandler’s particular version of this

A lot of pools in this city are twenty, thirty, or forty years old and have changed hands more than once. That matters here because of what comes after the algae.

When an old pool goes green and the plaster stains, the obvious answer is an acid wash. But every acid wash removes a layer of plaster, a pool has a finite number in it, and on a house you bought five years ago nobody knows how many it has already had.

So on an older Chandler pool, check the surface before anyone strips it. If it is chalking, an acid wash makes it worse and the honest answer is a replaster. The rough and chalky plaster page is the two-minute test for that, and it is worth reading before you book anyone.

What it costs

From the pricing page; the cost calculator prices yours now.

Do not leave it drained

If you drain it yourself, do not leave it empty. In summer sun an exposed shell heats enormously and plaster can craze within hours. A drain, wash and refill is run as one continuous job for that reason, and there are rules about where the water may legally go. See drained and now cracked.

Get a quote

A photo from the deck is usually enough to tell you which row above you are in, and often the answer is that you do not need us. We cover Chandler, Gilbert, Sun Lakes, Ahwatukee, Tempe, and Ocotillo.