When to stop filling CYA tube

[whiter0se]

Is it me or does this also happen to others?
I fill up the CYA “eye” tube until I no longer see the eye. I eventually reach 70ish before I stop but if I look closely I can see see the outline or at least some darkness from the eyeball. If I move around I can still see it, with my back against the sun and the tube at waist level.

I’m attaching a photo here but exactly when do we stop? Should I see the outline of the eye? Or are my eyes messing with me and it’s actually the shadow of the tube?
Thank you



Results as of today (6/11 - 11:45am) ;
5FC
0CC
120TA
200CH
7.5pH
70? CYA

 

[ajw22]

Call it 70 CYA and dont agonize over it. A 10 ppm difference in CYA does not matter. You have enough CYA.

Go swim.