High CYA/CH

[medvampire]

I think a drain and refill may still in order. You might want to take your pool water mix with distilled water half and half of each and test the dilution to see to see your level of CYA in the pool is at this time. This would give you an ideal your starting point to know the amount needed to drop that CYA level. I noticed your CH went up after refill so you may want to check your fill water for CH and ALK so you know what you are putting in to the pool. With that CH your ALK and pH needs to be a little low end to prevent calcium precipice and deposits.
Steve

[Gracy101]

I think a drain and refill may still in order. You might want to take your pool water mix with distilled water half and half of each and test the dilution to see to see your level of CYA in the pool is at this time. This would give you an ideal your starting point to know the amount needed to drop that CYA level. I noticed your CH went up after refill so you may want to check your fill water for CH and ALK so you know what you are putting in to the pool. With that CH your ALK and pH needs to be a little low end to prevent calcium precipice and deposits.
Steve

Geez - I'm lost....I get why he had/has to drain but I got lost when you and hulla started mixing water samples....Please explain in newbie terms

[chem geek]

Geez - I'm lost....I get why he had/has to drain but I got lost when you and hulla started mixing water samples....Please explain in newbie terms

The measurement test for CYA may max out at 100, so if you have more than 100 ppm CYA in your water the test will still show 100. That's what the "100+" means.

If you dilute your water by making a new mixture with half having your pool water (which has the 100+ ppm CYA) with half tap water (which has 0 ppm CYA) you end up with water that is a 50/50 mixture of the two so the amount of CYA in this mixture is the average between the "100+" unknown amount and 0.

So let's say you take this mixed (half diluted) sample to the pool store to be measured and now they say you have 70 ppm CYA. This means that your original undiluted pool water has double this amount, or 140 ppm CYA in it, because the average of 140 and 0 is 70 (that is, (140+0)/2 = 70).

Does that make sense?

Richard