Need to increase TA and have some xtra chems to use up. I have sodium bicarb from the pool store (="alkalinity up") which i assume is the same as baking soda. But i also have a bag of a bioguard product that is called total alkalinity increaser. It says it. Contains 100% sodium hydrogen carbonate. I just want to be sure this is the correct stuff before i throw it in the pool. It seems to be dosed the same as the alkalinity up.
Thank you!

They aren't the same thing. The baking soda is what you want to use. The sodium carbonate will raise your TA, but will really push your pH up at the same time.

What is your TA at now?

Wow. Glad i asked first! TA is 80. I have brand new plaster and a swg pushing the pH up daily so i have used MA daily to decrease pH. TA dropped and i dont want it to go below 80 since that is the minimum recommended in the pool heater manual. I have read quite a bit of the forum that says you can go as low as 60 to 70 but im not sure my warranty would still be valid if i did that.

Sounds like you're on the right track.

Stop! Sodium hydrogen carbonate is a synonym for sodium bicarbonate and is the same thing as baking soda. The Bioguard Alkalinity Up product you refer to is identical to baking soda.

It is sodium carbonate that is in pH Up products and that you don't want to use for raising TA since it also raises pH substantially.

Ack! Chem Geek is right. Duh

So, either one will work fine for raising TA I'm not sure if Chem Geek disagrees with raising TA, but I still think it is fine. Having it lower won't damage your heater, but I would be wary of the warranty issue as well.

You guys are so thorough. We noobies really appreciate it! I thought it was all the same since it was mentioned in pool school, but i have been "pool stored" enough in the past to make absolutely sure I know what Im putting in my pool before I add it!

Going lower in TA isn't going to damage your heater, but if anything did happen to the heater (for whatever reason) and the service people checked the TA and blamed you and didn't honor the warranty, well then that wouldn't be good for you. If you keep the TA at 80 ppm, you'll probably be adding more acid to keep the pH lower, but also keep in mind that with newer plaster curing that will raise the pH regardless of TA level. Right now, it's probably the plaster curing that is causing the bulk of your pH rise so having the TA at 80 ppm vs. a lower TA probably wouldn't be that noticeable a difference anyway.

I kind of suspected the plaster more than the TA or the swg for this year, but i was hoping to let TA drift a bit lower maybe in the next pool season or 2 once the plaster cures to try to decrease my acid use. I dont like to make anybody else but me mess with MA so it can be a challenge getting the acid in there daily when im not home! Thank you for your insights!