Best practice on order to correct chemicals?

[mhk.kohler]

Chlorine - 0.5
CYA - 0.0
pH - 7.0
TA - 70-80
CH - 125-150

I know I need to increase 1) CYA & 2) TA in order to help address the Chlorine & pH. Also need to increase the 3) CH.

Is there a best order in which to address these three? Or are they unrelated? Given how many adjustments I need to make, I’m not sure where to start & don’t want to add to the problems.

 

[mknauss]

TA is fine. pH will increase on its own with aeration.
FC is low, add 3 ppm FC per day until you get CYA dissolved and tested.
Add 40 ppm CYA using the sock method.

Add the chlorine now and start dissolving the CYA now.

 

[Panzer]

Chlorine should be your first priority. It is what keeps the pool 'healthy' for swimming. The CYA does need to come up but, in my experience it can take a few days to dissolve the stabilizer and get an accurate reading (it's what will help keep your chlorine level from dropping off).
Next I'd get the pH to where it should be ... you're not bad right now. A little aeration (splashing in the pool) will bring it up without chemical addition.
As for the TA... it will determine how easy it is for your pH to swing. Where you're at right now is not bad. May not be ideal but, I've dealt with worse.
Finally, I'd work on the CH... it can be a problem with plating out on some surfaces. I usually don't worry about it as I've got a vinyl liner. It's something that can be dealt with over time.

Also, you may want to consider a TF-100 or comparable Taylor test kit. The strips are notoriously bad at CYA and Chlorine levels (especially in the low region you're currently at).
Best of luck.
Respectfully,

 

[mknauss]

Also, you may want to consider a TF-100 or comparable Taylor test kit. The strips are notoriously bad

Good catch. Test strips are junk.

To be honest, unless this is a fresh fill of new water, I would add 3 ppm FC worth of liquid chlorine each day while you wait on the delivery of your test kit that Panzer referenced.

 

[mhk.kohler]

Thanks all! I am using the test kit, just need to update my signature (doing that now).