iggy said:
I have a Goldline/Hayward SWG and they want the level between 60-80.
Also they say this:
Without stabilizer, the chlorinator would have to produce much more chlorine in order to keep the desired residual level in the pool. Add enough stabilizer to be near the top end of the range at the same time you add salt.
I will wait until fall to lower water level and reduce my CYA to 80 ppm.
Most SWG manufacturers say to have a higher CYA level. That makes sense so that the cell doesn't have to work as hard (which means you would have to replace more often)
I don't know if I totally agree with the statement in bold though. What do you consider much more chlorine? The target level of FC is lower when your CYA is lower and its a near linear equation.
CYA ........... Min FC3 ..... Target FC ...... Yel/Mstrd Min ...... Shock FC ..... Yel/MstrdShock
10 ............... 0.81 ............. 1.21 .................. 1.61 .................... 4.5 .................. 7.1
40 ............... 2.9 ............... 4.6 .................... 6.1 ................... 16.0 ................ 23.8
80 ............... 5.8 ............... 9.1 .................. 12.0 ................... 31.42 ............... 46.12
120 ............. 8.7 ............. 13.6 .................. 17.9 ................... 46.72 ............... 68.42
Let's look at a few levels for comparison. At 80ppm CYA the target FC level is 9.1ppm which is half of the 40ppm CYA level of 4.6ppm. So realize that at the higher CYA level you need twice as much FC. So the key factor is what is your FC burn rate? if your FC level stays fairly constant than you may not need the extra CYA. On the other hand if your FC is being rapidly depleted (based on many factors) than the extra CYA may be beneficial. My burn rate may be totally different than your burn rate and the only way to know is by constant testing/data. Maybe your not doing alot of swimming. That would reduce your burn rate. So far this year, I'm burning alot more FC than at the end of last year (even at a higher CYA). I think its because we've just reopened the pool recently and we've done alot more swimming earlier and there's probably residual organics.
It really depends on what level you can maintain. It may be easier to maintain 4.6 ppm FC even though it's being depleted faster than 9.1 ppm FC. If it wasn't then why not raise your cya to as high as possible? Because you then have to maintain a much higher FC level which for BBB means much more bleach. What's easier, a small bottle of bleach several times or many gallon jugs a few times? You have to strike a balance and everyones situation will be a little different.