New pool owner wanting to do things the right way!

[dawei213]

Hi all, I posted a few months ago about the plaster in the pool that I just bought (dark-streaks-in-color-plaster-pool-t58183.html). But now that I have finally moved in, I can test the water and swim in it as well! I've never owned a pool so everything is new to me. I'd like to stabilize the pool using the BBB method and then figure out the plaster issue. Anyhow, here's my story and some questions I'd like to ask.

The first week I got into the house, I just did a basic test of the pool and the FC was 5 and PH was 7.8. The water was clear and everything looked good. Then I ran into the issue of the water falling below the skimmer opening. For 3 days, I was wondering why my pump was not working correctly. I called a local pool company to see if they can come out and take a look and they said in two days. Ok, but in the mean time I keep trying to troubleshoot. I didn't realized I was getting air into the system until I heard the suction of air through the skimmer. In any case, I filled the pool up to the halfway mark of the skimmer opening and the pump ran happily. Of course the very next day our area had a torrential downpour and pushed the water level ABOVE the skimmer opening. I guess I should always check the weather when my water level gets low. In any case, two days after the rain, I broke out the full TFT-100 test kit and got the following results:

FC - 1.5
CC - 0.5
TA - 130
CH - 220
CYA - 70

Now, at first I found a box of dichlor and cal-hypo. I was tempted to use them to bring up my FC. However, spending the few minutes on the forum using the search function, I found the pitfalls of using those products. As my CYA is already on the high end, I don't want to push it up any further. And since from one of the chart i've read that I need to bring my FC up to a target of 8, I didn't want to add those other chem that'll mess with the other values. So I drove to my local Target and got a few gallon of liquid bleach 8.25%. The pool calc told me I would need 2.21 gallons. Down they go the skimmer. Day after, tested again and saw my FC went up to 8.5. So it looks like I was able to bring up my FC relatively easy. However, my CC went down to 0.

Ok, so here are my questions:
1) How come CC went down to 0? What is the effect of having CC being 0?
2) I keep reading to reduce CYA, you need to drain and refill? Is it because CYA will always reside in the water and won't dissipate?
3) The bleach I purchased said 8.25% sodium hypochloride and below that it said 7.xx% (can't remember the exact value) chlorine. I'm assuming for the pool calculator, we will enter in the sodium hypo value? What's with the chlorine value?
4) What if I had my FC level to drop to that low level for a few days? Is it safe after I increase FC and maintain a few days?
5) How does the chemistry for my pool look?
6) How often should I do a complete test? Once a week? Once every two week? I know i'll probably be doing the Chlorine/PH test on a two day cycle if everything is stable.
7) Near the center of the picture, between the motor and the top white pipe, there's a metal spacer/gasket. There's a small leak while the motor is running. Is that ok? Or should it be completely sealed?



Thanks in advance for any answers. And looking forward to learn more!

 

[Isaac-1]

... In any case, two days after the rain, I broke out the full TFT-100 test kit and got the following results:

FC - 1.5
CC - 0.5
TA - 130
CH - 220
CYA - 70

Question 0 The pool calc told me I would need 2.21 gallons. Down they go the skimmer.

Chlorine should be added in front of the returns (same for acid) not down the skimmer, adding it to the skimmer can damage plumbing and pump fittings

...

Ok, so here are my questions:
1) How come CC went down to 0? What is the effect of having CC being 0?

Boosting FC levels and sunlight helps break down CC, a CC of 0 is a good thing, but often you will find some CC in pools as it is a byproduct of FC reacting with organics, some types of reactions produce more CC's than others.

2) I keep reading to reduce CYA, you need to drain and refill? Is it because CYA will always reside in the water and won't dissipate?

Yes, when water evaporates it leaves the CYA behind so to lower the level you must remove the water, CYA does slowly break down in a pool, but at such a slow rate that it would likely take you a decade to get down to our suggested levels, so we don't tend to talk about that much.

3) The bleach I purchased said 8.25% sodium hypochloride and below that it said 7.xx% (can't remember the exact value) chlorine. I'm assuming for the pool calculator, we will enter in the sodium hypo value? What's with the chlorine value?

8.25% bleach was introduced in the last year or so and has since nearly completely replaced 6% on store shelves (8.25%), however some parts of pool calculator have not been updated with an 8.25% choice, such as the effects of chemicals section.

4) What if I had my FC level to drop to that low level for a few days? Is it safe after I increase FC and maintain a few days?

It increases your chance of having an algae bloom, although there should be no reason to SLAM (shock treatment process) if you are not showing signs of algae, elevated CC, however you might want to do an over night chlorine loss test to rule out a low level algae problem (FC should not drop by more the .5 ppm from dark at night until dark in the morning before sunrise)

5) How does the chemistry for my pool look?

CH is a little low, you may want to use up some of that Cal-Hypo to boost it and FC for a bit, CH should be 250-350 in a plaster pool.

TA is a bit high, but that you can address later, it really is a secondary chemistry concern that too many people get too paranoid about

6) How often should I do a complete test? Once a week? Once every two week? I know i'll probably be doing the Chlorine/PH test on a two day cycle if everything is stable.

It depends on the individual pool, for now I would suggest FC and pH on the 2 day cycle, if your pH is steady and predictable you may move pH to every other FC test or even weekly, since you have a plaster pool I would suggest CH weekly for now, CYA and TA probably monthly, maybe less than that.

7) Near the center of the picture, between the motor and the top white pipe, there's a metal spacer/gasket. There's a small leak while the motor is running. Is that ok? Or should it be completely sealed?

It should be sealed completely, but small leaks like that are somewhat common, I have one on the output pipe from my pump (about 18 inches down stream from where yours is) at a threaded union fitting right now, it has been leaking for a couple of weeks, I will get around to fixing it when the weather gets cooler, of course is very slow I have a bucket under it and it takes 3-4 days for it to fill the bucket.


Hope this has helped some
Ike

 

[danacc]

A little more information on 3, 4, and 6.

3: For the pool calculator, use 8.25%. This is the amount of sodium hypochlorite there is in the bottle of bleach. The 7.84% value tells you the equivalent amount of available chlorine there is in the bottle. The pool calculator knows that the chlorine compound in bleach is sodium hypochlorite; it wants the percentage of sodium hypochlorite and not the equivalent chlorine value.

4. FC does 2 things. It sanitizes and it oxidizes. For safety to health, the sanitization aspect is important. To prevent algae, the oxidation aspect is important. From a health perspective, it is is safe to swim as long as the current FC reading is between minimum and slam levels. From an oxidation and algae perspective, letting it drop to 1.5 gives you a risk of an algae bloom starting, like Isaac-1 said.

6. I test for FC and add chlorine every evening. I'm new to BBB and I'm still learning my pool. I test for pH every couple of days.

 

[dawei213]

Thanks for the answers guys!

I'll be adding all my chems in front of the returns from now on now.

I re-tested my FC today and it was at 5, so a drop of 3 (I'm assuming all the values are in ppm?). I tested around 3pm this afternoon and it was overcast the entire day with some sprinkle of rain here and there. Although this is way past the overnight chlorine loss test, is 3 ppm in a 24 hour period loss with pretty much no sun too much? I guess the ON CLT would give me the best indication right?

As I won't be swimming in the pool for the next few days, probably until this Saturday, I decided to add in a bag of cal-hypo to raise the FC back up to around 8 and raise CH as well. As I understand, cal-hypo also raises Ph but it should decrease as FC drops back down. I'll continue to monitor and retest CH on Tuesday/Wednesday.

Although I did have the pool at a very low FC level for probably a day or two at most, I would guess there might be a risk of algae bloom. Looking at the pool, it looks clear and no hint of green anywhere. I'm guessing I dodge a bullet there? Or should I SLAM just to be on the safe side?

Also, it looks like I'll want to get that leak fix near the end of the season.

Thanks!

 

[danacc]

Yes, the FC and CC values are ppm.

The OCLT needs to be done between evening and morning. Even when it is overcast, there is UV from the sun, and that is what consumes the FC. The OCLT and CC reading in the morning are the best early indicators of an algae bloom. It takes a while to see the green, and the earlier you detect and deal with it, the easier to stop it. I wouldn't SLAM right away, but I'd run an OCLT tonight and also test CC in the morning.

Net effect of the Cal-Hypo should not change pH. It will raise both FC and CH which you already know (and a little salt - no big deal).

 

[dawei213]

Ok, this is more just for my own record but I did a FC test around 8:30 pm, sun already set for a while, and it came out to 7 ppm. I'll retest around 5:30 am to see what I get.

 

[dawei213]

Ok, FC was measured at 6.5ppm at 5:50 am, so a dip of .5ppm. CC was also at 0.5ppm this morning. I didn't check CC last night. So there's no need to perform any super chlorination?

 

[danacc]

Correct. You may want to keep an eye on the CC for a few more mornings, but it sounds like you've been smiled upon. Just maintain normal chlorine levels and swim!

 

[dawei213]

Great. I rechecked FC this morning and it was down to 4 with CC of 0. I added another bag of cal-hypo to boost the FC and CH to bring it back up to 7 then i'll add chlorine later on to raise it to 8. I think I"m getting the hang of this. Eventually I'll want to add borate to the equation but that won't be until next season since it's close to closing time.