New house / pool

[stalevel]

Hi all,
Thanks for all that you share! I've been reading around here for a few weeks now and while overwhelmed with all the info, I feel like I'm starting to see the light. I bought a house in this year with a pool in San Ramon, CA. The pool has been managed weekly by a service company for years and I've kept them on while I figure things out. In general, the pool looks great, but for some white "film" on the tiles, and I've been told it's the easiest pool on his route. I bought the TF-100 and have run all the tests twice in the last week or so. I figure I'll go a couple months watching what he's doing and testing, just to make sure I'm getting reasonable, repeatable data. Then I'll go it alone.

3/19/14 - 1 day after service
Temp - 60F
FC - 5
TC - 5.5
pH - 8.2 (Taylor kit)
TA - 70
CA - 125
CYA - 30

3/23/14 - 2 days before service
Temp - 60F
FC - 2
TC - 2
pH - 8.0 (Milwaukee MW102)
TA - 70
CH - 125
CYA - 30

I have way more questions than I should probably put in this post, but I'll start with the water and maybe add on to later posts. For one, we have had a lot of rain in the last month, and I have had to empty water from the pool. Not sure how much dilution has occurred as a result, but these tests were done after the rains. Our water here is incredibly low in all ions, which I'm guessing explains the relatively low alk. and hardness. The only obvious problem I see is the pH. My pool guy isn't adding enough Acid? Would this explain the white "lime" on my dark blue edge tiles?

Thoughts on a direction if I were to take over chemistry now? Start with acid. Then, should I build up TA and CH, or are they workable where they are?

Lastly, any locals care to clue me in to the best places for bleach, acid, etc.

Thanks again!

 

[Richard320]

Welcome!

For starters, rainwater doesn't really dilute things all that much. Figure out your average pool depth. Mine is 60". Yours is probably similar. 3" of rain is only 5%, and 5% of 125 CH is only 6 PPM. The test kit's not that accurate! You'd never be able to measure the difference. So don't worry about that.

I'm jealous of your soft water. If you want to raise CH, come on down and bring an empty barrel and I'll set you up. I have quite the opposite problem, so I have no advice to give on adding CH.

TA is okay. Just plug numbers into Pool Math and add whatever acid you need to lower pH to about 7.6. Pay attention to the CSI number down at the bottom, both now and targeted. As long as it's ⁺/- about .5, you're okay.

Your FC is too low, you're right at the minimum. So add some. The CYA is also probably too low, San Ramon is bright and hot so you'll lose a lot of FC to the sun come summertime. If the pool guy is using pucks, it will go up without any further effort. Maybe even go up too high.

Just keep studying Pool School, and pay close attention to what you're adding and how things change. Compare your results to what Pool Math shows under Effects of Adding Chemicals and compare. Your volume may be slightly off, and that's the best way to figure it out. And as you get some hands-on, you'll learn by doing and it will suddenly make perfect sense. It's really easy once you do it regularly. If you start now, by the time the water's warm enough to swim, you'll spend more time setting up the coffeemaker than you will dealing with the pool every day.