Why is dichlor not recommended?

[Farmingtonpool]

Just found the site and am learning lots already. Opened our pool this past weekend. Green algae present. Added Poolbrand "quick dissolving shock" which we have used in the past. After looking at some different posts saw that dichlor is not recommended for bumping up chlorine levels. Sodium dichlor is the 99% active ingredient in this product. What is a better alternative?

[Watermom]

Dichlor is ok to use if your CYA level isn't too high. Do you know your level? If your CYA is high, then using either plain household bleach (generic is fine) or liquid pool store chlorine are good alternatives. Also, if your calcium levels are low, cal-hypo may be a choice.

Do you have a current set of water testing results taken with a drops-based kit that you can post for someone here to look at?

Welcome to the Pool Forum!

EDIT: Looks like Janet and I were posting at the same time!

[Farmingtonpool]

Just have the basic test kit. Running 5+ on the chlorine, 7.6 on pH. Water slowly getting better. How can I check my CYA levels.

[PoolDoc]

Usually, we recommend that folks purchase the K2006 kit, which allows you to measure CYA (stabilizer) levels, and accurately measure chlorine levels above 5 ppm. There is a link, to various kits available from Amazon -- usually, the preferred seller there is Amato.

Alternatively, you can take your water to a dealer. The problem is that they often use test strips, and the CYA test is the worst of a bad lot -- we often refer to test strips as "guess strips" because they are so vague in their results.

What sort of pool do you have?

[Farmingtonpool]

Gunite, 3 1/2 years old. About 30,000 gallons.

[PoolDoc]

Yes, definitely, you need a K2006 -- you not only have to manage CYA levels, but you actually need to "balance" your pool water (manage pH, alkalinity, & calcium hardness) to protect the plaster and concrete.