Green water - not from algae or copper?

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Pool Newbie
Pool Newbie
Posts: 1
Joined: Mon 30 Jul, 2012 19:09
My Pool: 3700 gal Intex Easy Set
1600 GPH sand filter & salt water chlorinator

Green water - not from algae or copper?

Postby swimm7946 » Mon 30 Jul, 2012 19:27

Hello pool gurus! Water chemistry newbie here. So I just set up a small Intex 16' x 42" 3700 gal pool, with Intex 1600 GPH sand filter and salt water chlorinator. Just filled it yesterday. After filling and before "turn on" of the chlorinator, stats were:


My first step was to start lowering the PH, so I added 1 lb of BioGuard Lo 'N Slow PH reducer ( ... _Slo%C2%AE ) Almost immediately, the water started turning a crystal clear green.

After a couple hours, I also added 1 lb CYA, as advised by the Intex manual, as well as 2 oz of BioGuard SuperSol chlorine granules (since the SW chlorinator was not activated yet.) The pool turned even darker green.

My first thought was that the copper content in the water was high and causing a reaction with the chlorine. But copper test strips indicate 0 copper. What's going on? Iron?


Pool Newbie
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Joined: Tue 07 Aug, 2012 15:45
My Pool: My Pool uses many different parts.
Location: Oakville

Green water - not from algae or copper?

Postby OakParts » Tue 07 Aug, 2012 16:22

Hello There!

The best way to work from here is to shock the pool. You seem to have quite a large pool, and the free chlorine level is not in the correct range of 1-3 ppm. Shocking the pool (Concentrated chlorine shock) will increase the free and total chlorine as well as clear up your pool.

If none of this helps, and you still think that there may be iron in your pool, you could use a product such as "Metal-Free" that will deactivate all metals (either copper or iron) in your pool.

The green indicates an algae problem most likely, which would be caused by the lack of chlorine in your pool.

Hope this helps you out.

chem geek
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Green water - not from algae or copper?

Postby chem geek » Fri 10 Aug, 2012 10:43

Green can also be iron because yellow on a blue vinyl background looks green (yellow + cyan = green).

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