0 FC problem...

[Bob12NJ]

Hi, everyone! Name is Bob and I'm new to the forum. I've had my pool for 11 years, but have never had this problem. Just recently opened pool, it is looking good, but test done by my local store is showing 0 free chlorine. My CYA is 51. Any help?

[Watermom]

Hi, Bob. Give us some more information and we'll see if we can help you. What type of pool and what is the volume? What kind of filter and size of pump? Can you post a complete set of current water testing results taken with a drops based kit and post them, please. What all have you added to the pool, meaning ingredients and not just "shock." What was your CYA when you closed your pool last year? How much chlorine at at time have you been putting in the pool -- meaning, how high have you been shocking to?

Re-post with the requested info and we'll see what we can do.

[Bob12NJ]

I have a 27,000 vinyl liner. DE filter with 1.5 hp Hayward Super pump. Opened green pool with 5 lbs granular Bio Guard Super Soluble. Cleared pool up pretty well. 2 days later, took pool sample over to store and was told to ad a variety of products for ph and stabilization- also 6 bags of shock. Pool looks great, but test strips are showing 0 FC. Another test at pool store- still 0 FC. They told me to add 9 bags of shock. Test strip is still showing no chlorine, however, a test with my kit with the drops shows adequate chlorine. What is up?

[Watermom]

Trust your own numbers. Please post a current set of water testing results. Also tell us the ingredients of everything you have added, not just "shock." Do you know what your CYA reading was when you closed in the fall?

[CarlD]

Bioguard super soluable is Di-Chlor powder. But what were the other chemicals they told you to add?

Just so you know, the only things you should worry about with a green pool is pH and chlorine levels (I'll bet they sold you calcium carbonate, too, useless in vinyl pools).
You did say your CYA is currently 51ppm, didn't you? That means you need to shock your pool by adding chlorine till FC reads 15ppm.

I'm wondering if your FC is actually high and is bleaching out the test strips and the pool store's test, probably DPD.....

Try using an ordinary, cheap OTO test kit. If the chlorine test side is clear, you have no chlorine. But if it's yellow, orange or brown, you have LOTS of chlorine and it's bleaching out the other tests.

Carl