How low is too low for TA?

[Bensnorman]

My TA always seems to be a little low. It settles are 40ppm.
Here are my current test results.
FC:5
CC:0
pH:7.5
TA:50
CYA:40

On a few occasions I have added a lot of baking soda to being TA up to about 70, the adding acid to being pH back down. But after a few weeks, TA will settle back down around 40.

I have a 30,000G IG vinyl.
Any help is much appreciated.

 

[mknauss]

We recommend to be aware below 50 ppm. But if your pH is steady with a TA of 40, I would not mess with it.