CYA levels, need someone good at math

smooth2222

LifeTime Supporter
Oct 25, 2010
285
michigan
CYA levels, need someone good at math

over 6 months

a 50lb bucket of tricholor pucks would raise the CYA of a 15,000 gallon swimming pool by how much?


thanks, steve
 

smooth2222

LifeTime Supporter
Oct 25, 2010
285
michigan
yup, gonna have to switch to liquid bleach :)

thats what i figured. I have CYA of 110 with tf 100 test kit.
the dip in the water test strips screwed me, totally innacurate

so will probably have to do 2 step 40% drain and refill and start using liquid bleach
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
Keep in mind that the standard CYA test will show anything over 100 as the same thing. So you CYA level might be much higher. You can do the test with dilution to get an idea if your actual CYA level is close to 100 or close to 200, though you lose most of what precision there is. Mix equal parts of pool water and tap water, do the test on that, and multiply the result by 2.
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
Just be aware that the test is not that accurate at levels over 100, you might be better off retesting diluting you sample 1 to 1 with tap water then multiplying your result by 2. This will introduce its own error, but it will likely tell you if your in the right ballpark with the 110 reading, as that could well be 150 or 200 on the straight test.
 

smooth2222

LifeTime Supporter
Oct 25, 2010
285
michigan
just drained 1/3 of water and refilled. got my CYA down to 65-70 area, got some heavy rains coming so will be back washing it to drop it a couple more points.


so 1 tricholor puck in a 15,000 gallon pool with raise the CYA by how much?

just curious.

already bought some liquid chlorine
 

CUTiger78

Well-known member
May 24, 2009
465
NoVA
smooth2222 said:
so 1 tricholor puck in a 15,000 gallon pool with raise the CYA by how much?
How many pucks in 50 lbs, maybe 100?

If yes, then 1 half-pound puck would raise the CYA in 15,000 gals by 2.22 (assuming that Richard's original answer was correct).
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
42,945
Tucson, AZ
Go to the poolcalculator.com and put your pool size at the top. Then at the bottom you can see what adding different chemicals will do.

A 7 oz puck will raise FC by 3.2, CYA by 1.9, lower pH by 0.17 and raise salt by 2.6
A 8 oz puck will raise FC by 3.7, CYA by 2.2, lower pH by 0.20 and raise salt by 3.0