Confused with Chemistry of SWG

[purptiger]

Hello I am a new poster, but have been following for about 2 weeks this site. I have conflicting information on what to set my chemistry for SWG. I went to the pool school and read the basic article on setting the chemistry for SWG.

PS
TA 60-90 ppm
PH 7.5-7.6
CH 300
CYA 70-80

Resilence recommends
TA 110-180
CYA 60-80
Salt 3000-4000

Current Readings
FC 2
PH 8 (Just added 30 oz of MA)
TA 100 (not sure it I should count 1/3 of CYA amount?)
CH 225
CYA 60
Salt 4500
Setting only on 10 %
Temp 86 F

I am not sure if I should follow the PS of my manufacturer? I do have some scale on sides and bottom, but that is because I let it go and did not test consistently. I will look into this at some time soon. I do not want to do an acid wash so I am thinking about looking at Jack's Magic and a go stainless steel brush. Any advice is greatly appreciated. Luv FAS-DPD, but want to give Colr Q a chance. It is off, but in the ball park with the accuracy specs.

 

[chem geek]

Welcome to TFP! :-D

I would definitely follow the recommendations from the Pool School. The main difference you probably noticed is in the lower Total Alkalinity (TA) level recommended here. The reason is that SWG pools tend to rise in pH over time and this is at least partly due to carbon dioxide outgassing from the pool that is exacerbated at higher TA levels. Lowering the TA helps reduce this effect. The Resilence manufacturer may be under the mistaken impression that the greater pH buffering from a higher TA level will reduce the rate of pH rise, but they are neglecting to account for the fact that TA is itself a SOURCE of rising pH.

When you post TA readings, you do not adjust for the CYA level. The only time that becomes important is in calculation of the saturation index, but the adjustment for CYA is done automatically for you when you use tools such as The Pool Calculator. As for your current scaling, you can find more information in the Pool School under Calcium Scaling. Simply lowering your pH will help somewhat unless the scale is older, but it will usually require physical removal.