Is this treatment plan ok?

[Soximus]

Here are my morning test results— the pool just passed the OCLT test, so I’m looking forward to some swimming this afternoon (about 10 hours from now). Need to know what (if anything) I should do to the water between now and then.

FC 13.0
CC 0.0
pH 7.0
TA 120
CYA 35

Pool math is telling me to aerate and to add CYA to get all numbers in range.

Topic 1:
- Do you agree with that plan?
- Can I do both at once?
- it’s my understanding that you can add CYA right before you swim, (and that aeration is OK to do any time)?
- I’ve also read that swimming with high FC following a SLAM is fine, so I’m not worried about that FC number. Right?

Topic 2:
I’ve searched the forum and can’t find a concise answer to this: what is the “order of operations” for adjusting a pool with multiple levels out of range? Which can you definitely do — or not do — simultaneously? Which steps require time to pass before moving onto the next step, and how long are those intervals (1 hour? 2? 24?)

Thanks for your help!

 

[drsipe]

First, any PH reading with FC above 10 will not be accurate, giving you a lower PH value.

You can add the stabilizer now to raise your CYA to the proper. Then when the chlorine level drops to below 10 take another PH reading and if the PH is low aerate.

 

[CrystalRiver]

You cannot guess CYA numbers between the marks on the tube, because the scale is logarithmic. Always round up. Your CYA is 40.

You can adjust any and all parameters simultaneously, EXCEPT acid (lowering pH) and chlorine. Do one, let the pump circulate for at least 15 minutes (preferably 30), then do the other.

 

[Soximus]

First, any PH reading with FC above 10 will not be accurate, giving you a lower PH value.

You can add the stabilizer now to raise your CYA to the proper. Then when the chlorine level drops to below 10 take another PH reading and if the PH is low aerate.

Thanks. That note about FC and pH is definitely in the SLAM guidance! Just didn't retain the info after my first 10 read-throughs/viewings... sigh. Will do re: CYA.

 

[Soximus]

You can adjust any and all parameters simultaneously, EXCEPT acid (lowering pH) and chlorine. Do one, let the pump circulate for at least 15 minutes (preferably 30), then do the other.

Thanks! For FC and CYA, which I know are closely related, what's recommended? For example, say your CYA was too low, and your FC was also too low. I'd guess you'd get your CYA level up first, then deal with FC once you have a solid reading for CYA... which, depending on whether you're using liquid (fast) or granular (slow) stabilizer, might take a while?

I know pH and TA are also closely linked... are these the correct courses of action for dealing with these two levels?

pH/TA
Low/low: Add baking soda
Low/high: Add borax to raise pH and then MA to lower both OR add pH decreaser to decrease both and then aerate to increase pH only (which of these approaches is preferred?)
High/low: pH reducer + alkalinity increaser OR add baking soda to raise TA, then MA to lower both (which is preferred?)
High/high: Muriatic acid