test results..suggestions needed

[amieelynne]

Hi...
latest testing shows that my pH is a bit on the low side. so, after reading all around here I *know that I should add some borax...except when I put my info into the bleachcalc to see how much it tells me to "add 13.6oz of sodium carbonate (soda ash NOT borax)" ?!?! I thought you added borax to raise pH if your alk was in range? am I missing something or just having a blond moment?

test results from an HTH 5 way drop test
TC 3
alk 80
cya 30
Ph 7.2

17000g of water..give or take

 

[andysutt]

try this calcultor..
http://www.poolcalculator.com/

here is what i got putting in 17k gallons.

To raise PH from 0 to 1 add 78 oz by weight or 68 oz by volume of washing soda or soda ash
or add 156 oz by weight or 150 oz by volume of borax.
Note: PH calculations are approximate, exact numbers depend on ALK. These numbers assume an ALK level around 80-120. Changing your PH will also change you ALK level.

 

[andysutt]

or better yet...

To raise PH from 7.2 to 7.5 add 23 oz by weight or 20 oz by volume of washing soda or soda ash
or add 47 oz by weight or 45 oz by volume of borax.
Note: PH calculations are approximate, exact numbers depend on ALK. These numbers assume an ALK level around 80-120. Changing your PH will also change you ALK level.

 

[MikeInTN]

As Andy pointed out, roughly double the amount of soda ash recommended to get the amount of borax you'll need.

 

[duraleigh]

amieelynne,

My first thought is a pH of 7.2 is fine....I'd leave it alone unless it dropped lower.

Borax is best for raising pH. It's not in bleachcalc because the vagaries of pH rise are difficult to calculate.

 

[Guest]

You can add twice the amount by weight of borax for the soda ash and get approximately the same pH increase. It's not exact but it's close enough for government work!

 

[amieelynne]

thanks andy...that's the figures I got too. I also have that calc and ran it after I got the funky message from bleachcalc. now I can see that it was probably more the way I was reading it--I took their " NOT borax" to mean do not add borax to raise pH instead of the measurement being for a different chemical. that's sounds about as confusing as can be...but I know where I went wrong now

I know technically 7.2 is in range for pH...I always figured it was better to stay in the middle of range rather than the top or bottom--am I opening a chem can of worms by tinkering with the pH? I'm trying to get the pool stable so I don't have to micromanage it. I've been keeping the chl floating between 2-4 by adding bleach every other night...and that's not too much of a bother. haven't had to really add anything else since startup (except for the stabilizer ect needed in the beginning) ...all the while I watch my neighbors huff and puff and run to the pool store everyday, coming back with armfulls of chemicals I've directed them to this site, printed off the BBB sticky about pool chemistry and told them how easy and cheap it seems to be but they just don't believe me

 

[MikeInTN]

thanks andy...that's the figures I got too. I also have that calc and ran it after I got the funky message from bleachcalc. now I can see that it was probably more the way I was reading it--I took their " NOT borax" to mean do not add borax to raise pH instead of the measurement being for a different chemical. that's sounds about as confusing as can be...but I know where I went wrong now

I know technically 7.2 is in range for pH...I always figured it was better to stay in the middle of range rather than the top or bottom--am I opening a chem can of worms by tinkering with the pH? I'm trying to get the pool stable so I don't have to micromanage it. I've been keeping the chl floating between 2-4 by adding bleach every other night...and that's not too much of a bother. haven't had to really add anything else since startup (except for the stabilizer ect needed in the beginning) ...all the while I watch my neighbors huff and puff and run to the pool store everyday, coming back with armfulls of chemicals I've directed them to this site, printed off the BBB sticky about pool chemistry and told them how easy and cheap it seems to be but they just don't believe me

I wouldn't say it's a big can of worms. What I found with my pool was I had to adjust my TA until my pH would hold stable where I wanted it to be. I lowered my TA from around 160 to 100 using acid/aeration, and found that my pH was wanting to stay on the low side 7.0 - 7.2. I could add borax, and the pH would come up, and then go right back down over a day or so. I adjusted my pH/TA upward using baking soda until my pH started staying constant at around 7.4-7.6 . I checked my TA, and it's around 120-130. Now my pH hangs right around 7.5 - 7.6 .

 

[JasonLion]

I would bring the PH up, but not all the way to 7.5 in one go. There is plenty of room for the calculations, or the numbers they are based on, to be wrong. Plus it is almost always better to be gentle, take changes in small steps until you learn your pool. The major exception is shocking, where you want the chlorine level to go up a lot all at once.