Just guessing on chemistry up until now-new test kit, better numbers, where to go

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Meme26

Meme26

0
Dec 10, 2017
13
Luther, OK
Pool Size
250
Hi all, I am new to the forum and a new hot tub owner. I am just looking for some help to get a pool care routine established. Like many I started out with MFG instructions and when that didn't work I went to to the local pool store...So now I am at trouble free pools searching for my own answers.

My numbers for today are

FC = 3.6
CC = 0.8?
CYA about 21-22
TA = 100
PH = 7.8
CH = 120

From what I have read this looks about right and I have no idea how I got to that as I have been literally just throwing chemicals at this thing since I didn't have a good test kit until today.

I started out trying to use the SWG but the heater has to be off and I am not sure that it is worth it to let the temp drop and have to reheat every day.
Then the store suggested MPS as a shock so I used that thinking that it would raise the FC and not understanding why my FC was so low when I would test.
Next they sold me Di-chlor and I used that a few times but still seemed to be getting random FC numbers. I have since attempted to shock the tub up to 10 with 6% clorox bleach but it took twice what pool math told me to get it to go that high. My reasoning for shocking to 10 was just to try to see what my 24 hour chlorine demand was.

I can set my SWG for 3, 5 or 8 hours so I attempted to see how much chlorine it would generate in 3 and 5 hours and the numbers I came up with were about 1.5 in 3 hours and about 4 in 5 hours. In that 8 hours it lost 5 degrees.

I usually get in the hot tub every day for 30 minutes, clean with no lotion, makeup or suit.

Now for questions
1. How much chlorine loss is normal in a 24 hour period?
2. Should I attempt to use the SWG at all (it has to be turned on manually)
3. I am also going out of town for the week of Christmas and unsure of what to do while i'm gone. I dont want to drain because my daughter will be visiting for a week when I return and I don't have time to refill, heat and balance so we can enjoy the tub while she is here. Could I use tri-chlor for that week since my CYA is only 20 or could I shock high and lower the temp?

Sorry for the long post and thanks in advance for any help and suggestions.
 
Welcome to TFP and congrats on the new hot tub!

Here is everything you need to run your hot tub on bleach and/or the SWG. How do I use Chlorine in my Spa (or pool)?. I've been using this method in outmtub for 4 or 5 years now and it works great.

Answers to your questions
1. It depends. :) some testing and note taking will get you a general idea.
2. No real need to use it if it can't be put on a timer, it is easier and faster to add an ounce or two of bleach.
3. Lower the temp to 80ish or the lowest setting, raise FC up to shock level for the CYA, [FC/CYA][/FC/CYA], and float a trichlor puck or two.
 
Thank you Pooldv for your welcome and your answers to my questions.
Thank you for your welcome Texas Splash

Couple more questions
1. Is the FC/CYA chart the same for pools and hot tubs?

2. When I did my CC test I left the test tube to write down some numbers and when I came back the water was slightly pink again so I added anther drop of solution and it turned clear immediately. I just left the tube on the counter and when I checked a few minutes later it was slightly pink again. Is the true reading the one that happens instantly when you swirl it or should I keep dropping and watching until it never turns pink again?

3. Is it possible for pool math to incorrectly calculate on such a small hot tub? I'm still trying to figure out why I had to add so much bleach to get the FC up to 10.

4. or could I have checked it too soon. Is there a certain amount of time I should wait to check FC after adding bleach?

5. Also I have seen a rule of thumb for how much chlorine to add to account for bather load but I don't know where I saw it? and I
can't figure out in my mind how that rule of thumb is independent of pool size if someone could explain I would appreciate it.
 
Is it possible for pool math to incorrectly calculate on such a small hot tub? I'm still trying to figure out why I had to add so much bleach to get the FC up to 10.
Click to expand...

Bleach loses it strength over time. It evaporates into chlorine gas, and leaves the bottle.

Heat, sunlight, and the entropy of time are the enemies of bleach. Being half strength is not at all unusual in my experience.
 
This might also help:
1. The chart is used for all products, but you should also be familiar with the TFP (SPA Sticky): How do I use Chlorine in my Spa (or pool)?) - look for the summary at the bottom of post #1. :)
2. Disregard the pink after you stop mixing/stirring. Record the number right away and toss-out the mixture. It will change back to pink when you let it sit.
3. Make sure you are entering (manually) the correct WEIGHT (%) of bleach in that FC field. If all other data is correct, the calculator will do the job for you.
4. For pools we say about 30 min or so. In a spa, probably much less - maybe 10-15 min most.
5. See the sticky post above. :)
 
Ant 83 this was a brand new bottle of bleach I went to the store and bought just to shock the tub with. My hot tub is in a small unheated enclosure and so is not exposed to any sun and the temps right now are highs of 40s and 50s. Are you saying that even a new bottle might not be the strength listed on the bottle?

Texas splash thank you for answering the above questions especially #2 i was really confused by that. I have read the sticky multiple times but I keep losing track of where I read what:confused: :D
 
I have read the sticky multiple times but I keep losing track of where I read what
Click to expand...
It's a lengthy post and it can be overwhelming a bit. Just focus on these basics and the Vital Links you see below in my signature:
Summary

Water Balance
If your CH is much below 100 ppm, raise it to ~150 ppm. Otherwise, make a note of it.
Adjust your TA to ~50 ppm. Use Baking Soda to raise it (unlikely to be needed), or Acid/Aeration method to lower it. It takes ~8 oz Dry Acid to lower TA by 100 ppm in a 350 Gal Tub. Don't add it all at once!
pH should be between 7.2-7.8. Aerate to Raise pH. Acid to lower it.
If pH creeps up too much (>8.0), lower TA. If pH is too low, and doesn't raise enough by aeration, raise TA.
Add ~50 ppm Borate. (Borox/Acid or Gentle Spa)
Calcium, Baking Soda, Dry Acid and Borates is all you need to balance your water.
Use PoolMath to calculate exact amounts to add.

Sanitation
On a fresh fill use Dichlor until you get to 20-30 ppm CYA. (10 ppm FC = 9 ppm CYA)
Then switch to Clorox Unscented 6% or 8.25% bleach.
Never let FC drop to Zero for any length of time. Keep it between 3-6 ppm normally, min of 1 ppm, and shock to 12 ppm once a week.
Use MPS if needed before hot tub party's and/or once a week to help oxidation. Don't use more than needed, because it's acidic and may lower your TA/pH.
Dichlor, Bleach and MPS is all you need to keep your tub sanitized.
Use PoolMath to calculate exact amounts to add.

Lastly, get a drop test kit such as the Taylor K-2006 or a TF-100. Also get FC test strips. They come in handy for a quick FC estimate, during party's etc. The only two things you need to check regularly are FC and pH. Check them every day and after soaks. Adjust TA as needed. If you have your water well balanced, you'll rarely need to adjust your TA. You'll just be adding chlorine every day, and after soaks. Shock once a week, and/or after high bather loads. Use MPS if you have party's, and/or don't want to use as much chlorine. Easy as can be, and your tub is always ready.
Click to expand...
 
I just tried to look at the date on the bleach... I cant make heads or tails of it but i will keep working on getting this stuff figured out. I have not tried to use pool math for di-chlor since I didn't know about this forum yet when I used the dichlor. so I will try to check that on my next refill.

Thank you all so much for your help and for this forum in general.
 

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I just tried to look at the date on the bleach... I cant make heads or tails of it
Click to expand...
The bleach bottle should have a Julian Date ink stamp near the bottle neck or someplace something like this: "17330". That equates to the year 2017, 330 day. Old (smaller) numbers (i.e. 300 or earlier) mean the bottle was packaged earlier in the year. So you want a larger number which = fresher bleach. :)
 
pooldv said:
3. Lower the temp to 80ish or the lowest setting, raise FC up to shock level for the CYA, [FC/CYA][/FC/CYA], and float a trichlor puck or two.
Click to expand...

I may be over thinking this but do I need to let the temp drop to 80 and then shock or just shock and turn the heater down regardless of how long it takes to cool off? also my lowest setting is 65 so do I need to turn it down that low or is 80 good enough?

On another note my spa seems to have a 5ppm demand in 24 hours with no bathers at 101f. Is that normal?
CYA = 22
FC=2.6
CC=.4
TA = 100
PH = 7.6
CH = 120
 
I hope I'm interpreting Pooldv's note above correctly. I think his note above about lowering the temp to 80 or lowest setting was simply to save energy since you mentioned being out of town for a few days. So lowering the heat and floating a puck or two helps to maintain sanitation and increase CYA slightly while you are away. But you can add the bleach at anytime as needed. An FC demand of 5ppm with no spa use looks to be a bit excessive. But that's where the SPA sticky link above comes in handy. One example, "Shock at an FC of 12 once a week" to help give your water that extra punch for sanitation. So if you haven't done that yet, it's probably time. If you still see a high demand, you may need to maintain the FC of 12 for a day or two to see if that helps. If that doesn't work, you mentioned doing the water swap after your daughter's visit, so that may be the next step.
 
Thank you for the reply TX. I assumed that lowering the temp would help to preserve the FC which is why I asked the above question.

Also From some of the threads i have read I also thought I understood that if there were unwanted things in the tub using up the chlorine that the CC would be higher than I am seeing. Is this not correct?

On days that I don't use the tub I am adding 1.5 oz of 6% bleach to account for 5ppm demand and on days when I do use the tub I am adding 2.5 oz of 6% bleach to that amount to account for bather load of 1 person for 30 minutes of use. I am consistantly testing at 6:00 pm each day and getting a reading of 2.8-3.2 ppm so I seem to have it under control but I just feel like 5ppm demand is a lot.

Most days I do use the tub so according to pool math adding 4oz of bleach would raise my FC 9.2 - added to the 3ppm that is already in the tub when I test would effectively be raising it to 12 if I am understanding all of this correctly, right?

Sorry for all of the questions, I just want to make sure I understand.
 
Your FC use is similar to mine and at first I was concerned because this is not what I experience with my pool system. Now that I have had more experience with using chlorine in my spa I am more at ease and attribute the difference to the high heat and water volume (225g). That said I do intend to do a full clean with Awesome when I do the next drain and refill which I always do after about 100 days. After I use the Awesome and refill I will check any difference in FC use.

The primary concern for me is the FC ppm when we intend to actually get into the spa and I want it to be between 2 to 4ppm. I primarily use the spa in the mornings and evenings and will add chlorine at the rate of 1.5 oz per bather and that will allow the FC to drop below 5ppm after 10 hours or so. Also on days that I don't use the spa I too add the 1.5 oz.
 
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