As I stated above our water has high CH. I am surprised it is 400 CH in your area. I would assume you are getting Colorado River water out of Lake Mead. It's CH is ~250 ppm.
I have no knowledge on the borates and bees. If you wish to add borates, read Borates - Why and How
If you have a CYA of 30 and you last drained in Nov 2017, how are you chlorinating?
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When you do the CYA test, try this next time.
Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Pour the solution back into the mixing bottle and redo the test several times. Take the average of your results and round up to the nearest whole 10.
The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
Thank you , I only use liquid chlorine for the pool (bleach). I think about the borates.
I would like to find a solution the wasp that are flying over to our pool to take a little dip. [emoji4]