Test your fill water and rain

[Countrygirl]

Thanks to the BBB method and this forum I was able to quickly clean up my swamp water. For the past two weeks I have been trying to get my TA down to about 90 using the MA method but at the same time I was cleaning dead alga from the bottom of the pool by vacuuming to waste. I could not understand why my TA would at first go down then go back up. I read in an earlier post about high TA levels in the fill water so I checked mine and sure enough my fill water tested TA at 240. So needless to say when I refilled my pool each time after vacuuming I was also increasing my TA!

Since I am all out of MA and must go to the store and buy some more I thought I would ask if anyone knows how much I should buy to get my TA down to 90. Also, is 90 a good place to be, my pool is in the sun most of the day, I have a vinyl liner AGP, 23,000 Gal. Here are my current test results using the TF test kit:

FC 5
PH 7.5
TA 110
CYA 60

Thanks for all your help.

 

[JohnT]

I wouldn't worry about a TA of 110. I can only dream of TA that low.

 

[Countrygirl]

I was under the impression that if the TA was lower it would help stabilize my PH. At this point when I bring my PH down to 7 it will increase to 7.5 or 7.6 in a matter of 1 1/2 days with out any additional aeration. Last year, I had to keep adding PH down, this year I wanted to avoid that. Have I understood this wrong? Is it normal to keep adjusting the PH every other day?

 

[AnnaK]

Good advice! We should all know the chemistry of our fill water, just as it's important to know your pump pressure when the filter is clean, i.e. right after a backwash.

 

[lovingHDTV]

It will take ~14 cups of 31.45% acid.

Don't add it all at once, just enough to get your PH to 7.0, then after aerating add more to get you PH back down to 7.0.

Hope this helps,
dave

 

[Countrygirl]

Thats great Dave, thank you. How did you figure that out? Is there a sticky or TA calculator out there that I missed? Is 90 a good place to stop?

 

[Butterfly]

Hi countrygirl,

The info you are looking for is in the "Stickies" section located at the top of each page in the sub-headings, also a link in my sig.

You can determine your chemical doses with Jason's Pool Calculator and there is a sticky on lowering your TA.

 

[lovingHDTV]

Last I looked, Jason's calculator will not tell you how much acid to add to lower TA, just PH. It is one thing that I find missing as my fill water TA is very high and I need to keep my TA around 60.

Sometime ago chem_geek posted an excel spreadsheet that does provide this, it is what I used. It is a pretty complex spreadsheet, but I like it. Not sure if he is still posting it anywhere, so I'm hesitant of posting it myself.

Maybe it is in the stickies, I don't know.

 

[Countrygirl]

Thanks Joyce, I have been using the pool calculator and following the instructions found on the How to lower the TA sticky, its all very helpful, thats how I was able to clean my swamp in a very short time and for a lot less $$$. What I don't see is a way to calculate the total amount of MA needed to decrease the TA. I am lowering the TA and keeping a chart showing my results each time I add MA so I can always refer back to the chart in the future. I was just wondering if there is a way to predetermine it.