Maintaining chemicals after pool startup

Mirage21 · Feb 14, 2014

Hello,

My pool has been re-plastered (white plaster) for about a month now. The company did the startup and everything looks great so far. Dust cleared in less than a week, a lot of brushing and vacuum helped. The only hand off instructions given to me was that I needed to add chlorine and acid for now.
So I’ve done a lot of testing with the K2006, and here are the results so far (with measurements taken 5 days go as well):

Current readings:

FC = 0.5 (was 4.0 five days ago)
CC = 0
pH = 7.8 (was 8.0+ and I added one gallon of acid to lower it, now it’s back to 7.8)
TA = 130 (was 130-140)
CYA = 32
CH = 400 (was 320)

1) Does it usually take weeks for the pH to stabilize?
2) Do I need to constantly keep it in range DAILY?
3) If the calculator calls for adding 1 gallon of acid, is it safe to dump the whole thing in or slowly do it? Just curious if I’m going to need to buy like 10 gallons of muriatic acid or something. I have 2 left =P.

I’ve been trying to keep the chlorine in level. I already added 2 quarts of chlorine since it’s dropped down a bit. Since this is spring, would lower levels be safe since nobody is swimming in it yet or should I just aim for higher levels? It does get some sun, but this is Socal we’re talking here. My pump is running about 4 hours daily.

jblizzle · Feb 14, 2014

1. pH does not necessarily stabilize. With your higher TA and the new plaster, the pH is going to constantly drift up. Any aeration will also drive the pH up.

2. Yes, until you get a feel for how quickly things change. You will need to add bleach daily.

3. 1 gallon is a LOT of acid, confirm the calculation. It is safe to add all at once by SLOWLY pouring it in front of a return jet of water in the deep end. And after, running the brush real quick ensures it is not sitting on the bottom.

You need to ALWAYS maintain the recommended FC levels in the FC/CYA Chart regardless of season or use.

Richard320 · Feb 14, 2014

Mirage21 said:
...
Current readings:

FC = 0.5 (was 4.0 five days ago)

CC = 0

pH = 7.8 (was 8.0+ and I added one gallon of acid to lower it, now it’s back to 7.8)

TA = 130 (was 130-140)

CYA = 32

CH = 400 (was 320)

1) Does it usually take weeks for the pH to stabilize?
2) Do I need to constantly keep it in range DAILY?
3) If the calculator calls for adding 1 gallon of acid, is it safe to dump the whole thing in or slowly do it? Just curious if I’m going to need to buy like 10 gallons of muriatic acid or something. I have 2 left =P.

I’ve been trying to keep the chlorine in level. I already added 2 quarts of chlorine since it’s dropped down a bit. Since this is spring, would lower levels be safe since nobody is swimming in it yet or should I just aim for higher levels? It does get some sun, but this is Socal we’re talking here. My pump is running about 4 hours daily.

It can take a while for pH to settle down, especially with your high TA. The amount of acid you need for a certain pH change will drop as the TA drops. Play with http://www.troublefreepool.com/calc.html a little and see for yourself.

You should check pH daily until you get the hang of it. You might not need to adjust it every day, but you won't know that until you test it a while. As long as you're between 7.2 and 7.8 you'll be fine. As for adding the acid, just dribble it in the pool in front of a running return. A thin stream, slow enough not to glug and splash you and burn holes in your clothes, is what you want.

You need to raise FC and keep it above minimum all the time. Period. The good news is that you won't actually need as much to replenish this time of year as you will in the summer. Which segues nicely to the next paragraph.

To answer the question you haven't asked: your CYA level is too low.

Given the climbing pH, the low CYA, and the low FC, you'd be a good candidate for using the hated trichlor pucks in a floater or chlorinating using dichlor "shock". Read the label carefully!! Not all "shock" powders are alike. If you plug your numbers into http://www.troublefreepool.com/calc.html and scroll waaaaay down to Effects of Adding Chemicals, you can see what adding these powdered chlorines will do to your water. Just don't buy more than you need to raise CYA and then measure and add it as needed to chlorinate.

Bama Rambler · Feb 14, 2014

1) Yes it takes weeks or longer before the pH settles down. Just keep testing and adjusting it every day or two.
2) I would test it every day and no longer than every other day.
3) Chems should be added slowly in front of a running return. It's perfectly fine to add the full amount that poolmath calls for. However with large pH adjustments, you should add less than called for and retest.

Mirage21 · Feb 14, 2014

Given the climbing pH, the low CYA, and the low FC, you'd be a good candidate for using the hated trichlor pucks in a floater or chlorinating using dichlor "shock". Read the label carefully!! Not all "shock" powders are alike. If you plug your numbers into http://www.troublefreepool.com/calc.html and scroll waaaaay down to Effects of Adding Chemicals, you can see what adding these powdered chlorines will do to your water. Just don't buy more than you need to raise CYA and then measure and add it as needed to chlorinate.

Are the trichlor pucks hated because it's hard to gauge how much is going in the pool (i.e. timing of when you take it out of the pool?).
I am not so familiar with the use of pucks, but i have a floater ready. Do i just monitor daily and take out when ready?

pwrstrk · Feb 14, 2014

At the bottom of pool math you'll find effects of adding chem's. Enter your puck weight and it will tell you how much CYA each one will add.

Richard320 · Feb 14, 2014

Mirage21 said:
Are the trichlor pucks hated because it's hard to gauge how much is going in the pool (i.e. timing of when you take it out of the pool?).
I am not so familiar with the use of pucks, but i have a floater ready. Do i just monitor daily and take out when ready?

They are hated because they insidiously add CYA continuously. People buy a huge drum of them when they're on sale, then get cloudy water from insufficient FC for the CYA level. And then the pool store sells them hundreds of dollars' worth of treatments they'd never need if they hadn't overused pucks. Until they diagnose high Total Dissolved Solids - which the CYA created -- and they recommend water replacement. That's why. Also, pucks are acidic and lower pH all the time, which might not be bad where we live, but it can lead to real problems where people have naturally soft water. We're not opposed to using any form of Chlorine here, as long as you are aware of the effects. So if you need to raise CH and Cal-hypo is on sale, use it. Just don't overuse it. Likewise with trichlor and dichlor. Know what it's doing and only use what you need and things will be fine.

Figure each puck is probably 8 oz if you don't have a scale, then don't use more than you have to to raise CYA. I'll toss 3 in the feeder and let it go. Instead of removing the pucks if FC gets too high, you just close the adjustable opening in the floater. If it sounds too complicated, don't bother. Manually adding CYA granules by filling a sock and letting it dangle will raise CYA. The rest is easy to cure with bleach and acid, just like you've been doing.

Mirage21 · Feb 15, 2014

To answer the question you haven't asked: your CYA level is too low.

So i've purchased some trichlor pucks and started using them. I've put in 3 pucks based on the calculator estimates to raise my CYA by 3.8 (to 35.8) and chlorine to about 6. (From the ""Effects of adding chemicals"). Help me understand something: why is my CYA considered too low when i thought the ideal range is somewhere between 30-50?

For this CYA/FC chart: if my current level is 32, then isn't my target FC at 4? I found in the description that the "The target FC level is a minimum. You always want the FC level to be at least as high as the target level." I find that somewhat confusing because there's minimums and targets stated.

Lastly, should I do anything with my high TA for the time being? I think what I can do to lower it is to stop having the SPA aerate into the pool. There's lots of bubbles/waterflow that come out of the spa area due to how I've set the return valves (it's on half pool, half spa).

Thank you all for your inputs so far!

Richard320 · Feb 16, 2014

Mirage21 said:
So i've purchased some trichlor pucks and started using them. I've put in 3 pucks based on the calculator estimates to raise my CYA by 3.8 (to 35.8) and chlorine to about 6. (From the ""Effects of adding chemicals"). Help me understand something: why is my CYA considered too low when i thought the ideal range is somewhere between 30-50?

For this CYA/FC chart: if my current level is 32, then isn't my target FC at 4? I found in the description that the "The target FC level is a minimum. You always want the FC level to be at least as high as the target level." I find that somewhat confusing because there's minimums and targets stated.

Lastly, should I do anything with my high TA for the time being? I think what I can do to lower it is to stop having the SPA aerate into the pool. There's lots of bubbles/waterflow that come out of the spa area due to how I've set the return valves (it's on half pool, half spa).

Thank you all for your inputs so far!

It's because you live in sunny SoCal that you want CYA higher than 30. You will lose less FC to sunlight if it's closer to 50. You will learn, when you've been weaned off the pucks, what your pool's appetite for bleach is, and then you can gauge how much you will lose every day. What you target every day is enough to keep it above minimum before you add again. Right now, it's hard to grasp. Once it warms up and you really start using the bleach, it'll all make sense.

TA is only a problem if you're at risk of scaling. Otherwise, don't worry about it. You bathe in that same fill water! It's just baking soda dissolved in water, basically. Having the spa aerate the pool is what drives pH up, which you lower by adding acid, which also lowers TA. So... ultimately, in a roundabout way, aerating the pool is what will lower TA. Don't obsess over it. Run enough through the spa so it gets its share of chlorine and doesn't get stagnant and relax.