Ken,
Glad the pool is clear! Algae monsters can't take the high cl levels and retreat as you have found. Now, you just have to make sure it never comes back by diligently maintaining proper water chemistry. Chem Geek has steered you towards the test kits we recommend. Hope you'll consider getting a good kit. It will make taking cared of your pool a lot easier.

Try the dilution method and see if you can get some readings and then repost.

BTW -- I merged your new post into the original thread. Better to keep all the information together to make it easier for us to help.