Low TA Question - Maintaining pH at constant level

[trbvm]

My stenner pump coupled with my pH Sense & Dispense system is excellent at keeping pH at a constant 7.5 always...

The pool levels are as below - This has been pretty much the same for the last several months.

FC - 5
CC - 0
TC - 5
pH - 7.5
TA - 40 <- issue?
CH - 325
CYA - 50

The only variable has been TA. This has been slowly going down from 60-70 and is now around 40.
Is it time to bring the TA up to 60 by adding baking soda? --- Or should I just leave it as it is now?

There are no problems with the water.
TIA

 

[pooldv]

I would probably bump it up to 50 and see how your PH behaves. 40 is a tad too low. About how much MA is it adding per week/month? Maybe set it to keep PH at 7.6 or 7.7.

 

[trbvm]

I would probably bump it up to 50 and see how your PH behaves. 40 is a tad too low. About how much MA is it adding per week/month? Maybe set it to keep PH at 7.6 or 7.7.

Thanks.. yes, I will bump it up to 50 using pool math values..
I am requiring about 1.5 gallons of MA per month .. not sure if that is a lot or normal. I read somewhere that the ORP probe requires the pH to be 7.5 constant. Anything above/below 7.5 makes the ORP values swing wildly and the chlorinator kicks in ..

By trial/error I have it now stabilized so that ORP values around 650 maintains a constant 5 FC with pH @7.5

 

[pooldv]

Sounds good! Don't mess with success. Adding a little baking soda occasionally to raise TA is no big deal at all. Nice work!

 

[trbvm]

Any recommended methods to add baking soda? I am using my Arm and Hammer Kitchen stuff... Planning on mixing with water and adding to skimmer.
Edit: Never mind. Read about this in pool school ... Going to sprinkle this in the surface of deep end.