Need Some Guidance with Chemistry

[notime2work]

I’ve been reading this forum since before we started our pool in February, so have learned a lot along the way. Our builder completed our pool last week, and had his folks come out and do the startup chemistry. They added the salt at the end of last week, and have now turned us loose with the pool maintenance. It has been difficult working around all the rain and thunderstorms, but began working with the T100 test kit and trying out hand at the Pool Math app. Here are the results so far:

FC – 2.5
CC – 1
TC – 3
CH – 300
TA – 120
CYA – 20

pH – 8.4

Salt level – 3300 (PB recommends 3600, so probably need to add)

Using the Pool Math app on my phone, I added 2 qts of muriatic acid to knock the pH down, but haven’t done anything else yet, until I get some guidance from you all.

1 - According to PM, I should add 3 gal + 1 qt of stabilizer for the CYA. What kind of stabilizer, and is this amount correct? Or should I get some of the chlorine tabs and put them in the skimmer until the CYA raises to the recommended amount?

2 – It also said I need to add 31# of calcium chloride. Is this the salt or something else?

Please let me know if I have left anything out. Also, I’m not sure what order I need to do all this, or do I add it all at one time. I’m a little confused and don’t want to mess things up, but after using the T100 a couple of times, I feel like I can master this eventually. It’s kind of overwhelming at this point. Thanks for any help you can offer.

 

[Richard320]

Recheck that CC reading. It's possible that it's correct and more sunlight will eliminate it. It's also possible that the builder added some MPS "shock". It's more likely a testing error. But if it's still there, something is up.

Also, don't bother testing TC with the yellow drops. The FAS-DPD test is so much better.

Don't raise CH any.

I wouldn't waste money on the liquid CYA. The granular stuff will only take an extra day to dissolve. Note that if there is a problem with CC (and/or water clarity) that you don't want to elevate CYA too much until it's resolved.

Confused? Normal. It'll take a couple weeks and then all the sudden it will all make perfect sense. It's just that learning by doing that takes time.

Just repeat the FC & CC tests for now and post back.

 

[Mr Bruce]

1. They sell it at Walmart/Lowes/HD. Make sure it says 100% cyanuric acid and nothing "blue" What # are you targeting? The SWG recommendation is 70 but it would be best to aim for lower than that, retest and then adjust, rather than overshoot.

2. Again, what is your target? 300 is fine for CH. Adding that much would raise you to 450 if my math is correct.

You're doing fine

 

[notime2work]

Recheck that CC reading. It's possible that it's correct and more sunlight will eliminate it. It's also possible that the builder added some MPS "shock". It's more likely a testing error. But if it's still there, something is up.

Also, don't bother testing TC with the yellow drops. The FAS-DPD test is so much better.

Don't raise CH any.

I wouldn't waste money on the liquid CYA. The granular stuff will only take an extra day to dissolve. Note that if there is a problem with CC (and/or water clarity) that you don't want to elevate CYA too much until it's resolved.

Confused? Normal. It'll take a couple weeks and then all the sudden it will all make perfect sense. It's just that learning by doing that takes time.

Just repeat the FC & CC tests for now and post back.

The pool builder did add shock when starting the pool chemistry. They also used 3 chlorine pucks in the skimmer basket, which have since dissolved. I'll retest the FC / CC / pH and post back later today. I really don't understand the CC info at all. In regards to testing TC with the yellow drops, are you referring to the drops in the blue box included with the TF100, or one of the solutions in the kit itself? I tried out the tests in the blue box just to see what it was about, but could not discern the color differences well enough to make sense to me. I like hard numbers better.

 

[Richard320]

In regards to testing TC with the yellow drops, are you referring to the drops in the blue box included with the TF100, or one of the solutions in the kit itself? I tried out the tests in the blue box just to see what it was about, but could not discern the color differences well enough to make sense to me. I like hard numbers better.

Yes. And perfect. The yellow drops are there as a sanity check if the other test gets weird. Just ignore it.

 

[notime2work]

1. They sell it at Walmart/Lowes/HD. Make sure it says 100% cyanuric acid and nothing "blue" What # are you targeting? The SWG recommendation is 70 but it would be best to aim for lower than that, retest and then adjust, rather than overshoot.

2. Again, what is your target? 300 is fine for CH. Adding that much would raise you to 450 if my math is correct.

You're doing fine

At this point, I'm not really sure what to target with the CYA or CH. I'm sure at some point it will click and make sense, but it's all a blur right now. I will start low with the cyanuric acid and test from there. To complicate matters, we have had a LOT or rain in the past 2 weeks, which makes it harder for me. I'm going to go back and re-read the pool school info this weekend. Thanks for the response.

 

[Texas Splash]

At this point, I'm not really sure what to target with the CYA or CH.

We'll keep it simple. A low CH really doesn't apply to vinyl pools. ANY pool is concerned with a high CH, so there's no need to add any for you. As for the CYA, normally salt pools need a minimu CYA of 70, but Richard noted making sure the CC is elevated either from lack of sun (to oxidize those CCs) or possibly from the junk the installers dumped in there. We like the CC to be at 0.5 or less. So before you increase the CYA to 70, I think he wanted to make sure all was well to elminate the need for a "SLAM". So just watch the water for now and keep the FC balanced to your current CYA as noted on the FC/CYA Levels. That's the key to avoiding algae. Don't worry too much about rain. It doesn't have a huge impact on what we do, just check your FC and CC a little bit more for the next couple days to ensure the water doesn't have an unusually large organic load in it.

Once we (you) know the water is crystal clear, the CC level doesn't not stay elevated, and there is no chance for algae, then you can increase the CYA to "70" which is more ideal for a salt pool. Let us know if you have anymore questions.

 

[notime2work]

Here are my current readings as of this morning:
FC - 4
CC - 0
TC - 4
CH - 300
TA - 110
CYA - 35
pH - 7.4

The muriatic acid managed to knock the pH down well. I bumped the SWG up a couple of %, so guessing that is why my chlorine level is up. My CYA is still low, and haven't added anything yet. Water looks good and clear. Please advise if I need to add the cyanuric granules to bring the CYA up to the recommended level for a SW pool.

 

[Msch99]

Looking good! Best thing I did on our pool was hook up with these folks. Pool is envy of the neighborhood!

FYI, round up to nearest number on the cya tube. Half way between 30 and 40 isn't actually 35.

 

[notime2work]

Looking good! Best thing I did on our pool was hook up with these folks. Pool is envy of the neighborhood!

FYI, round up to nearest number on the cya tube. Half way between 30 and 40 isn't actually 35.

Yes, I was SO glad to find this website before we even had ours built. It showed me there was a whole lot better way to maintain a pool than hiring a pool service. It was also so helpful to have guidance about knowing the equipment to purchase.

By rounding up to the nearest number on the cya tube, do you mean round up numberwise (to 40) or up the tube visually (to 20)? I did question this, but didn't know whether to round up to 40 or up the tube to 30.

 

[mknauss]

Round up in value. So if you find the level between 30 and 40, use 40 ppm CYA for FC, etc.

 

[Texas Splash]

By rounding up to the nearest number on the cya tube, do you mean round up numberwise (to 40) or up the tube visually (to 20)? I did question this, but didn't know whether to round up to 40 or up the tube to 30.

For the CYA, is it's 35 or more we round up.