before I add...

[bubbles]

Just had our first major pool party of the season yesterday and so today it's all about getting the chemistry back to norm...it will be the first time I have had to add anything besides acid or bleach, so I want to make sure I do it right. TA was at 50, went to PC and to get it back to 100 it said to add 141 oz of baking soda, if my math is correct, that is 17 cups give or take. Does that sound about right? Seems like alot, but then again, the only place I have been using the baking soda is in the HT and a tablespoon is all I've ever added there.
Thanks.
B

 

[jasonknox]

I am not sure about the math or your particular situation but TA of 100 would be to much for my pool. I have a steady ph rise and am trying to get my TA down to 60 to 70 to stabilize my PH fluctuation.

 

[bubbles]

I was just going by what the TFP test kit said, but come to think of it, my TA has been around 70-90 prior, so maybe I should stick with that. What is the difference in adding by weight and volume? According to PC, if I want to get TA to 70, it's adding 70 oz by weight or 56oz by volume...how exactly would I measure that out? ( and I also covert to cups to make it easier on me)Please pardon the learning curve...my math skills have always been less than stellar.

 

[JasonLion]

By weight is measuring with a scale, by volume is measuring with a measuring cup.

If you put the mouse over the quantity there is a status area that will show you the quantity in cups or quarts or gallons or whatever is appropriate.

 

[Bama Rambler]

It's the difference between liquid and dry oz's. Most solids are sold by weight not volume so when measuring it you can weigh it or you can use measuring cups. If you use measuring cups then you need to know how many liquid oz (measuring cup oz) equals 70 oz of weight. And it works out with baking soda that 7 cups equals 4.375lbs.

It's easier to let the PC do it for you as Jason said.

 

[bubbles]

Thanks for pointing out the conversion spot on the PC, I somehow missed that! LOL, I will need to retest everything here shortly as we just got a huge dose of golf ball size hail!! WOW!

 

[wimpy]

I use this site for all around conversions
http://www.onlineconversion.com/

 

[chem geek]

I was just going by what the TFP test kit said...

You are right. The TF-100 kit I have (the case is a few years old now) does say under "Total Alkalinity test" that "Good T/A readings will be around the 90-120 range." If newer kits still say that, then this should be changed to say something more like "Good T/A for pools using bleach, chlorinating liquid or Cal-Hypo is 60-90+ ppm" or something like that. The Recommended Levels in the Pool School distinguish between pools with and without a saltwater chlorine generator.