Re: Bought a Pool and it came with a houses.
Hello Mark,
Oh I hate that it didn't come down more for you with this drain/refill. I was hoping, and had my fingers crossed. I'm at least hoping the continued top off gets you to at least 70 or less, but that's not looking promising, but only time will tell. Of course anything 70ppm, and up per the Chlorine /CYA chart
http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock are not recommended as I'm sure you are aware. It is not recommended because it is not practical in attempting to reach the high FC levels that are required to prevent algae growth. Plus the extended high FC levels can also result in liner/equipment damage if left that high for too long.
But to answer your question I would hate to see you have to drain again for a 3rd time, and you've come such a long way already. Of course getting your CYA lower in order to run the lower FC levels would be the best option to prevent having to attempt to reach such high FC levels, risking not meeting a high enough amount to maintain at the Shock level, plus less risk for equipment damage. But since the CYA is still hitting at 85 rounded up to"90" If you are aware of the potential risks, and want to keep doing the partial drains, and refills like you have been to attempt to get it down soon then I can't say I wouldn't blame you for attempting it that way for a short period of time.
Of course, continue to allow the FC to drop to 10ppm or less in order to properly get your pH adjusted 1st, and then continue to refill, keeping your fingers crossed that the remaining top off lowers your CYA even more in the process. With the pool party this weekend that's about all you can do at the moment.
Others with more experience than I may come back and advise you differently or have better suggestions, so please follow their suggestions over mine should that occur, but if I were in your place with 2 drains/refills already, and slow moving well water to refill, that's exactly how I'd continue on, But the choice is yours.
I hope this helps, and have a wonderful night.