Adjusting pool chemistry

[p.p.h.]

Quick question. Is there one thing that I should adjust before the other if multiple things need adjusting? For example, should acid be added to lower ph before adding baking soda to raise alkalinity? Or borax before bleach etc? Is there a rule of thumb for this stuff??

[DavidD]

To me, Ph is the one with the most urgency, followed by chlorine, Alk, CYA then CH (as I have fiberglass). CH (calcium) would probably be second with a gunite/plaster pool. Also, Chlorine and baking soda could be added in succession without any problems but I would let acid mix a little before adding chlorine.

[waterbear]

My 2 cents:

It would seem that adjusting ALK first and then getting the pH in line is the way to go (unless the pH is WAY out of whack) since adding bicarbonate might cause a pH raise. IF both pH and ALK are too low then use sodium carbonate to raise both at the same time but do it in small amounts and test so you know where you are! If the Alk is too high then you are adding acid anyway as part of the lowering process. After the ALk and pH are where you want them you can raise the CH. Don't try to adjust ALK and CH at the same time or you could end up with a cloudy pool! (If the CH is way too high then you have a different set of problems and need to check your fill water to see if dilution is a workable solution. This should probably be your first step then.)

Get the CL and CYA in right away....you don't want a green pool! Any changes they might make to the pH will be small. Also be aware that any other products you might add such as metal removers can have an effect on the pH also.

For normal maintenace adjustments of CL and pH I would put in the bleach and wait a bit (maybe 15 minutes or so) so it can mix and then add my acid or borax to adjust the pH. A good brushing is always helpful to mix the chemicals you add directly to the pool