Pool is green

[georgepoolboy]

pool chorine leves ok ph leven ok after dumpping 5 lbs of shock,but still green. been going to local pool experts, first sweep floor add 3 lids of mustard , an 1 1/2 of shock for three days ,did tht, Iwent back cause it was still green, ,oh it s got metal,,soo i got metal out, went back next day,, ohh put some 25 lbs of calcium,do not backwash.pool still green,,I went back,,oh add 5lbs of shock, next day water still green, just like doctors,,,bleeding you slowly,,help, any suggestions?

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[dallas25]

What are your exact numbers of ph and chlorine. Does your powder chlorine have a stabilizer (CYA)?

[Bjorn]

Quite basically, you can control your poolwater by first regulating your pH value (6.8 to 7.2) and then shock with chlorine several times (after reg. of your ph-value again) until the water is crystal clear. Remember to backwash your sand filter continuously. Use granulated chlorine.

[chem geek]

Bjorn,

You have been recommending granulated chlorine in several posts, but what specifically are you talking about: Cal-Hypo, Dichlor, Lithium Hypochlorite or even powdered Trichlor? The following are chemical rules that are independent of concentration of product or pool size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.

So granulated chlorine products are not innocuous and lead to a buildup of either CYA or CH (unless you are referring to lithium hypochlorite, but that's VERY expensive). Chlorinating liquid or bleach will not add any CYA no CH to the water and the increased amount of salt added is much more innocuous than CYA or CH.

Richard

[Bjorn]

Hi Richard
I know that there are primarily 3 different types of chlorine to use, depending on the effect you want to achieve, and how and how your water chemical balance is. Cal-Hypo is rapidly soluble and is typically used for shock chlorination. The disadvantage is the increasing calcium hardness (CH) as you describe. I use it mostly for shock chlorination.
Triklor is slowly soluble and I typically use it to the ongoing continuous disinfection. And yes it increases CYA. Diklor are often used spa and for shock chlorination, but again - it increases CYA. So yes granulatet chlorine kan be a lot of types.

[jmb]

Perhaps you have a high iron content in your water causing the green "chemical" reaction to occur when adding chlorine. Adding something like HTH stabilizer should help or ask the local pool shop on what to use.