Reverse Osmosis treatment and now water balancing question

[zonkakiick]

Excited about a new start. My new build is coming up on 9 months old and the CH was already in the 650 range, so I started looking for alternatives before the heat of a Phoenix summer arrives. After the usual great advice I found on this site, I came across the RO service. The tech who did it put some chlorine in and left me (on my asking) to add the CYA.
He has a Taylor test kit, like I do. He found the following after adding the chlorine:
FC: 2
TC: 3
pH: 7.8
TA: 70
CH: 70
CYA (from Leslie's): 10

I also added about 2/3 of a gallon of liquid CYA. Based on my pool size, I'm guessing it will bring it up to 20, or so. I'll test it in 24 hours, then probably dump the rest in and try to get it to 30. Is that a good target? I only use liquid chlorine, so not sure if I should raise it to 40. Does being in a climate like Phoenix matter?

The CH is my concern. With a really hot summer coming very quickly should I just let the CH rise on its own to the 200+ level (because we know it WILL get there in Phoenix)? Or should I bump it up a bit to 150? I'm just not sure. I've read that low CH can be really hard on the equipment and probably other stuff as well (pebble tec?). Does it take a long time of low CH to cause damage?
So leave it and let it rise on its own, or bump it up with chemicals?
Also, with the water in this state, is a TA of 70 too low?
Thanks for all the help you guys give on a regular basis.

 

[Rancho Cost-a-Lotta]

I wouldn't want CH to be below 200 ppm for any extended amount of time. At that level, your water is starving for calcium so it will take it from plaster surfaces. Make sure your tracking CSI on Pool Math. Your's may be too aggressive with such a low CH level. Keep CSI between 0.0 and -0.30.

I assume your fill water is high in CH. Have you considered a water softener? Do you have a whole home system? If not, consider a dedicated system for the pool or look into an RV softener (see my sig). It's not the best solution but it does work.

For CYA level, target 60 ppm for now. We recommend 60-80 ppm for SWG pools. See:

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

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