Is Low TA a huge problem?

[JodieM]

I have a stand alone 250gal hot tub.
TA 40.
PH 7.8

If I lower the PH, I’ll end up lowering the TA. The PH does drift up to 8’s slowly over a month.
Last time I added baking soda to raise PH over the winter, it turned the water blue, tub blue, filter blue and coated everything. I’m hesitant to do that again.
Is TA 40 too low?

 

[Texas Splash]

40 would be my rock-bottom number. Anything lower and I'd a just enough baking soda to get the TA back to 50-60 and play the pH control game again. The blue would seem to be color coming off of the tub's coating. Is it acrylic, fiberglass, etc? @JoyfulNoise your opinion please?

Also, we is your CYA zero? That would really make the FC exponentially strong to the surfaces and bathers. Did you increase it already?

 

[JodieM]

40 would be my rock-bottom number. Anything lower and I'd a just enough baking soda to get the TA back to 50-60 and play the pH control game again. The blue would seem to be color coming off of the tub's coating. Is it acrylic, fiberglass, etc? @JoyfulNoise your opinion please?

Also, we is your CYA zero? That would really make the FC exponentially strong to the surfaces and bathers. Did you increase it already?

The tub color is light gray, it’s a rotomolded plastic material. It has a dull, matte like appearance with a light texture. The water was clear before I added the baking soda. I did add it dry instead of ore dissolving. We drained and refilled with fresh water I’m May.
I don’t use CYA in my hot tub because we keep the cover closed unless we are in it. My normal FC is 2. We used it last night and this afternoon and the chlorine was down to 0.5 so I gave it a little mini shock with liquid chlorine when we got out of it today so it’s ready for heavy bather load at tomorrow’s 4th of July party.