new home, new pool, new pool owner

[Hydrophile]

Just purchased my first home and it came with a pool. I received my Taylor K-2006 in the mail and tested the pool for the first time. My readings were as follows:

12,000 gallon aggregate surface pool
Sta-Rite PXC125 filter
Using 3" puck Trichlor in auto dispenser

FC 4ppm
CC 0.2ppm
pH 7.6
TA 60ppm
CAL 360ppm
CYA 80ppm

According to these levels, I would need to bring my alkalinity up. Is there a calculation that i can use to find the amount need to add?

[PoolDoc]

Your PF is 12; baking soda is functionally about 56% 'alkalinity', so a pound of baking soda adds 12 x 1 x 0.56, or ~7 ppm alkalinity. Don't add too much at one time. Five pounds (12 x 5 x 0.56 = ~34 ppm) would be a good dose.

It ends up being more complicated than that, because baking soda ALSO raises pH. Instead of trying to calculate doses, do this:

1. Use muriatic acid to lower your pH to 7.2 (your TA will also drop). Read the guide to MA use in my signature, FIRST though!
2. Add 6 lbs of baking soda.
3. Wait at least 4 hours of pump ON-time, then retest pH. If it's above 7.4, lower it to 7.4 - 7.6.
4. Then, test TA again.
5. If the TA is low, re-run the process.

There's no hurry: you are NOT going to damage your surface with a CH =360 so long as your pH is above 7.0. I wouldn't try to get the TA much above 100 ppm; high TA complicates things more than I usually talk about here.

More importantly, you need to read the Best Guess chart, and adjust your chlorine levels based on your CYA=80 level. If you end up with algae, THEN you'll have real problems!

[Watermom]

My first suggestion is for you to stop using the trichlor tabs. They are stabilized which means they have CYA in them. Your CYA is already plenty high. You actually should be keeping your chlorine higher than 4ppm. Take a look at the Best Guess Chlorine Chart in my signature below. With a CYA of 80, your chlorine should be between 5 to 10 ALL the time or you risk an algae bloom.

Regarding raising the alk, it is probably going to take around 7 lbs. of baking soda but you do NOT want to add that much of anything all at one time! Add a lb. at a time slowly to the skimmer while the pump is running. Wait at least 2 or 3 hours or longer, retest and redose until you get the alk somewhere around 100. Take your time. You don't want to cloud your water.

Welcome to the Pool Forum!

[PoolDoc]

Ah. we were working at the same time!

[Watermom]

Gee -- that's never happened before, has it?

I also see your emphasis on the N!

[PoolDoc]

Yeah. I think other people are mis-reading it, too. I can't help being an "old man", but I think I'll try to stay away from owning the "dirty old man" moniker!

I'll have to change it to "Muon inspector" or something. Susan prefers "Quark inspector", so maybe I'll use that.

[Hydrophile]

PoolDoc, said "Your PF is 12" in your response to my question. I tried to Google the abbreviation PF but don't know what it stands for...and how is its value 12?
I added four pounds baking soda by mixing it in a 5 gallon bucket and slowly adding it to my pool. I will test again tonight. I purchased liquid chlorine and plan to add some tonight to bring my level up to spec with the Ben's best guess chart.

Thanks for the timely response.
- The new guy =)

[PoolDoc]

PF is the ratio of your pool to a million pound (PF:1) pool. 1 pound of something with a 100% concentration (like good stabilizer) will result in a 1 ppm increase in levels in a million pound pool, but in a 12 ppm increase in a PF:12 pool.

It's something I've used for years, but only started using here this summer. (I need to write a "How to Use Your Pool Factor" page )