Need help with CYA for startup

[jnd5309]

Help! The water truck was here last Wednesday and I diligently followed the instructions in the article "Beginners Guide for Seasonal/Temporary Pools". Added enough chlorine to get it to 6 ppm the first night, and jumped in. After our first swim I added dichlor as directed for the four days. (Wed, Thurs, Fri, Sat). A week later and still no CYA reading at all. The test solution doesn't even begin to cloud up. It's good that my water's clear and all, but it sure would be nice if it clouded up when I tried to make it cloudy! I'm thinking there's some in there, as I'm not losing all of my chlorine during the day (pool is in direct sunlight late morning into early evening). This morning was the first time my FC dropped to below 4, and I've not added anything since Saturday.

My numbers from 5:15 am:
FC = 2 (added bleach before I left for work this am.)
CC = 0
pH = 7.5
T/A = 70
CYA = 0
CH = 50

Big question -- do I stop on the way home and get CYA, or is there something else I'm missing?

 

[JasonLion]

Welcome to TFP!

There are basically two possibilities. Either the CYA test is not working, or the CYA level is just below the threshold that the test can detect. Depending on which CYA test you are using the detection threshold might be 30 ppm or higher.

Which CYA test are you using?

 

[Puffin]

Sometimes dichlor is sold in lesser concentrations. What does the package you're using say about the concentration of dichor. The seasonal pool guide is expecting the 99%+ stuff.

I found this out the hard way, when I was first opening my pool. I couldn't figure out why my CYA wasn't going up and chlorine seemed low. The Aquachem stuff I was using was like 40% or 50% dichlor.

 

[jnd5309]

Thanks for the quick responses, guys. CYA test is that which comes in the TF-100 test kit. Don't know the concentration of the dichlor off the top of my head, and I've thrown out the packaging already. I'll slide by Lowes and check it on the way home.

 

[JasonLion]

The CYA test in the TF100 can report levels as high as 20 as if they were zero. The seasonal pool instructions are designed to raise CYA to 30, but it wouldn't take too large of an error for CYA to be under 20.

 

[jnd5309]

Sooooo - I assume I move really conservatively here? And tell the calculator it's at 20, just to be safe?