I’ll share my high CYA experience with you and offer a couple of educated suggestions.
In July of last year I converted to the methods here and started my own testing after reading a lot in the pool school and forums. I quickly determined my CYA was getting out of control. Too much trichlor and dichlor usage! I started out with a reading of just under 80 based on my own testing.
I used the pool calc page at http://www.troublefreepool.com/calc.html to determine what percentage to drain to go from 75 to 50 CYA. Recommendation was to drain 33% of my 16x32 estimated 22,000 gallon pool. I then used the pool volume calculator near the bottom of that page and a simple set of spreadsheet calculations to determine I needed to swap approximately 7300 gallons which would require dropping the pool a total of 24 inches based on my pool dimensions. I planned to do this in 6 drains of 4 inches each. I used a tape measure the first time and eyeballed it from there on out. I actually did a total of eight drain and refills of between 2 and 6 inches. (You will need to do more draining if you don’t do the drop all at once, as you are simply diluting less each time.) I did this over the course of two weeks depending on available free time to drain and refill so that my skimmer was operational most of the time - ie personal preference. I set the valve to waste and used only the floor drain to let the pool pump drain it out. I kept track of the estimated volumes drained each time and purposefully overshot to an estimated total of 7900 gallons and 26 inches.
I checked CYA once in the middle to determine effect and once at the end to confirm I was just under 50. Then over the next month I was fortunate enough to get nearly three inches of rain and also did a lengthy backwash and drain to waste for another swap of two inches. This put me at a CYA reading of just over 40 for the remainder of the season.
My suggestion to you is to order the test kit ASAP and start making a plan similar to above. Using pool math page tells us that “if” (and that is questionable) your CYA is at 300, you would need to drain 83% to get to CYA of 50. If it was me and water is cheap (your opinion and mileage may vary), I would plan to do two drains of about 25% to get started. Just be sure to keep water level above the bottom step and make sure you can get the water level back up to the return jets within 5 or 6 hours to ensure the pool stays circulating.
As far as estimating chlorine bleach to add, that is nearly impossible to know without adequate testing. Pool math indicates that at CYA 300 you should be at a FC level of over 23. That’s just crazy and impossible to manage. The unfortunate thing is that with your stated cloudy water condition, you probably already have an algae problem waiting to turn green. If it was me, I would consider adding a full gallon of 12.5 percent bleach or the equivalent at a lower percentage every day until I got the test kit. That would take you from FC of 2 to 12 at this point (or 0 to 10 if you have algae). I’m sure others with more experience will have some suggestions on this, but you are really driving blind without the test kit.
You add the bleach by pouring slowly (pencil size stream) in front of a return jet to disperse it through out the pool.
Good luck and order the test kit today at a minimum.
In July of last year I converted to the methods here and started my own testing after reading a lot in the pool school and forums. I quickly determined my CYA was getting out of control. Too much trichlor and dichlor usage! I started out with a reading of just under 80 based on my own testing.
I used the pool calc page at http://www.troublefreepool.com/calc.html to determine what percentage to drain to go from 75 to 50 CYA. Recommendation was to drain 33% of my 16x32 estimated 22,000 gallon pool. I then used the pool volume calculator near the bottom of that page and a simple set of spreadsheet calculations to determine I needed to swap approximately 7300 gallons which would require dropping the pool a total of 24 inches based on my pool dimensions. I planned to do this in 6 drains of 4 inches each. I used a tape measure the first time and eyeballed it from there on out. I actually did a total of eight drain and refills of between 2 and 6 inches. (You will need to do more draining if you don’t do the drop all at once, as you are simply diluting less each time.) I did this over the course of two weeks depending on available free time to drain and refill so that my skimmer was operational most of the time - ie personal preference. I set the valve to waste and used only the floor drain to let the pool pump drain it out. I kept track of the estimated volumes drained each time and purposefully overshot to an estimated total of 7900 gallons and 26 inches.
I checked CYA once in the middle to determine effect and once at the end to confirm I was just under 50. Then over the next month I was fortunate enough to get nearly three inches of rain and also did a lengthy backwash and drain to waste for another swap of two inches. This put me at a CYA reading of just over 40 for the remainder of the season.
My suggestion to you is to order the test kit ASAP and start making a plan similar to above. Using pool math page tells us that “if” (and that is questionable) your CYA is at 300, you would need to drain 83% to get to CYA of 50. If it was me and water is cheap (your opinion and mileage may vary), I would plan to do two drains of about 25% to get started. Just be sure to keep water level above the bottom step and make sure you can get the water level back up to the return jets within 5 or 6 hours to ensure the pool stays circulating.
As far as estimating chlorine bleach to add, that is nearly impossible to know without adequate testing. Pool math indicates that at CYA 300 you should be at a FC level of over 23. That’s just crazy and impossible to manage. The unfortunate thing is that with your stated cloudy water condition, you probably already have an algae problem waiting to turn green. If it was me, I would consider adding a full gallon of 12.5 percent bleach or the equivalent at a lower percentage every day until I got the test kit. That would take you from FC of 2 to 12 at this point (or 0 to 10 if you have algae). I’m sure others with more experience will have some suggestions on this, but you are really driving blind without the test kit.
You add the bleach by pouring slowly (pencil size stream) in front of a return jet to disperse it through out the pool.
Good luck and order the test kit today at a minimum.