Hey Nensea,
I am so glad no one else was home with me while I was reading about how you pranked your husband because I was laughing my heiny off....

You are just a little mischievous aren'tcha, now. :slidehalo: I love it! Of course he'll never again gather up any laundry when you want him to...
Your CYA has been all over the place from 25 to 80 to 40 to 30 (did I miss any?).... I have a feeling you aren't doing that test properly, and since it affects the FC you must SLAM at, it is
critical that you measure it
properly, and
consistently... Being at the proper FC level for
your CYA will speed up your SLAM. (or rather not being at the right level will make it last longer than it needs to...)
Here are some tips for doing the CYA test:
• It's recommended that you do the test while standing outside with your back to the sun and the view tube shaded by your body.
• Try to test at about the same time each day, so that you are getting the same effects of the sunlight each time. If you test once in the late evening and the next time at high noon, you may get different results… even using the exact same sample. (You can test this out for yourself—see below)
• While holding the skinny tube with the black dot at waist level, begin dripping the mixed solution into the skinny tube. Watch the black dot until it's completely obscured. Then, raise the tube up to eye level and look at the scale that is imprinted on the vial.
• Your CYA should be read at the line where the solution came up to. If the fluid level was in-between values, round up to the next higher number. The scale isn't linear, so mid-way between, say 40 & 50, is not 45.
• After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, give it another little shake, and do the test again a second, third, or fourth time.
• You can also use this same test mixture to try different things i.e. varied lighting conditions and other changes, to see what effects different testing conditions can have. For example, try any of the following: holding the view tube higher than waist level; or facing the sun; or view the test indoors; or in the shade on the porch; anything else you can think of to compare.
• Consistency is arguably the most important test parameter in CYA measurement. The margin of error (MoE) is +/- 10ppm regardless, so as long as you are doing things exactly the same way every time, then you'll be within the MoE.
• What you really don’t want is to have results be different only because you tested inside once and outside facing the sun a different time, or some other such. Pick a way, and stick with it!
Tftestkits.net sells an item called "CYA standard solution": which is a premixed sol'n with a CYA level of 50ppm. This is a great little tool for learning how to do the test perfectly... If you need to order refill reagents anytime soon, you may wanna pick some up at the same time.