Newbie Needs Direction

[ffde31]

Hi everyone,

Well, I'm new to the hot tub world and lovin' it. I am trying to get a handle on the maintenance chemical schedule. I have a 425 gal Down East Spa. I am having a little trouble keeping the chlorine and ph levels within normal range.

I have read many posts on this forum and have learned alot. Here's my info:

By the way, my Taylor kit is on it's way, I've been using a plain water testing kit to test my levels.

Today's numbers:

Alk = 90ppm

pH = 7.8 this seems to creep up daily.

Chlorine = 0.5ppm

We use our spa (just 2 of us) nightly for about 1 - 1 1/2 hrs. (no suits). We have been playing with the amount of bleach we add after use just to see what it does. Last night we added 3 oz ultra, earlier in the day it had been used by my husband after which he added 2 oz ultra. All together yesterday we added 5 oz ultra bleach. The tub has not been used yet today and when I tested the levels they are as above.

So I added 2 teas. of Dichor. I keep reading about the dichlor not being good to use all the time because of it's affect on the cya. (my level was <30ppm). We have only used the Dichlor on intial fill and 2 other times, low amounts. We are really wanting to use the bleach for everyday maintenance. Just haven't mastered it yet. Also, what can I do to stabilize the pH better? I like to keep it about 7.5 but can't seem to keep it there without using the pH decreaser.

My recomm.'s from the dealer are to add "spa shock" 2 oz, every other day...I see on the ingredients that the shock consists of 58% dichlor and 42% other ingredients...What do you think about that?

Also, how often should I be checking the cya level? Is it normal for the chlorine to dissipate that much overnight? The tub is covered.

I know this can't be too hard, I could just use some direction. I hope this post makes sense. I am trying to give all possible information - if I've missed anything, please let me know. I just know the Chem Geek and Waterbear will have my answers!! I am anxious to get comfortable with these chemicals. Please Help..

Thanks for your time.

[chem geek]

I suggest just using Dichlor until you get your CYA to around 20 ppm or so. This is around 2.25 ounces weight of Dichlor. My guess is that this is somewhere around 1-2 fluid ounces so that's 6-12 teaspoons total (cumulative). Then you can switch back to your bleach. 5 fluid ounces of Ultra bleach, if it's 6% bleach, (Ultra store brand is usually 6%; Clorox Ultra may be 7-8%; Clorox Regular is 6% -- see what your bottle says on it, if it does) should result in 5.7 ppm FC so that's how much you seem to be using which is high, but that's partly because you don't have enough CYA yet to keep the chlorine from outgassing so much. This should get a little better over time, though I still expect you to use a lot of chlorine if you use the hot tub as much as you indicate -- that's no problem, just add it after you get out. It might be interesting for you to see how much chlorine is lost in between when you get out, turn off the jets, and add chlorine until the next time you take off the cover and measure chlorine again (before you turn on the jets and get in). I suspect most of the loss is during your time in the spa, but this can verify that.

You do not need to use spa shock. Instead, you should buy non-chlorine shock, potassium monopersultate, and use that weekly (scale down the amount for your spa -- it might only list pool quantities).

You won't need to check on the CYA level again once you've added your Dichlor and gotten it to around 20 ppm (your test kit might only test down to 30 ppm anyway, so it's somewhat of an estimate based on adding 20 ppm FC worth of Dichlor cumulatively). You could check it after a month just to see that it's still there, but it should be (if not, add more Dichlor).

NOTE: The non-chlorine shock will be acidic so it's weekly use will likely take care of at least part of the pH problem, but read below for a procedure to lower the TA, BUT first get to using the non-chlorine shock since that will help somewhat. Though I describe lowering the TA to 50, you should probably lower it to 60 first and see how that is for you. If you go too low, then the non-chlorine shock you add might make the pH go lower than you want.

As for the pH rise, you can lower your TA level quite a bit. Ironically, the easiest way to do that is to run your jets (i.e. to aerate), but do so at low pH (7.0). It will take 1.5 ounces weight (about 0.6 fluid ounces or 3-4 teaspoons) of dry acid (sodium bisulfate) to lower your pH to 7.0 and then you'll need to run the jets (which will make the pH rise) and add acid to keep the pH at 7.0 and continue this until you get your TA to 50 ppm. It will take about 4.4 ounces weight (about 1.7 fluid ounces or 10 teaspoons) of acid cumulatively (not all at once, of course). Once your TA is at 50, stop adding acid but continue to aerate. The pH will then rise so stop aerating when the pH gets to 7.5 and could actually use 7.7 as a target pH since the pH rise should be less at that pH (especially with the lower TA).

At this lower TA, you should have a lot less outgassing of carbon dioxide and a lot less of a pH rise. I am assuming that you have no exposed tile with grout or anything like that -- the lower TA will be corrosive to plaster/gunite/grout unless the pH and CH are kept up. Most hot tubs don't have that, but I thought I'd ask to be sure. Over time, you can monitor your TA and increase it since it may go down some over time (or might not -- you'll have to see).

Be sure and let us know your progress and if this works for your pH rising problem.

[ffde31]

Hi chem geek,

thanks for all the vital information. I did neglect to mention that our tub does have an ozonater, i suspect that this will not change the advice you gave.?

We used the tub tonight for about 45 min, checked the chlorine and it only went down to about 4 ppm. After adding the dichlor earlier, the chlorine jumped to about 5ppm. I did not add anything after use tonight and will check the levels tomorrow before I get in. we'll see.

If I understand correctly, I need to bring down my alk. to 60ppm, pH will follow. I can aeriate to bring the pH back up. I also need to continute with the dichlor until I get the cya levels up to 20 to 30 ppm. My kit meaures only down to 30ppm. Does the Taylor kit measure to 20ppm? I take it I should add the dichlor in increments over time. My kit only measures total chlorine level I'm not sure I understand the difference btwn free chlorine and combined chlorine and active chlorine?...?? I assume that one is actually working at killing off bacteria while the other is just floating around smelling..?

Good to know about the shock, I will get the non-chlorine shock asap. and use it once a week. This in addition to the dichlor?

I'm trying real hard to understand all this..Hopefully you remain patient with me..

Thanks again so much!

[chem geek]

The ozonator (if working properly) should shock your pool water so you will not need to use non-chlorine shock. So in that case, lowering the TA is the way to go for sure. Keep in mind that the use of an ozonator will breakdown some of the chlorine as well so even with more Dichlor you may still see significant chlorine usage. That's just part of the price of using an ozonator with chlorine. It doesn't have this problem with bromine and can reactivate bromide (but can produce some bromate by-products).

The standard Taylor K-2006 only measures down to 30 ppm, but it's somewhat easy to see that the black dot is going to disappear somewhere beyond 30 ppm. Besides 30 ppm isn't horrible. Taylor does sell a separate test kit just for CYA that measures to 20, but that's more expensive. Yes, you add the Dichlor in increments over time -- just add what you need for raising FC and realize that you add to CYA by almost the same amount.

You should get the Taylor K-2006 test kit since that will test everything you need including Free and Combined chlorine separately (the chlorine test is called FAS-DPD and is drop-based where you count the drops and multiply by 0.2 or 0.5 depending on the sample size). Yes, Free Chlorine doesn't smell (or smells very faintly like the "clean" smell of bleach) and is the active form of chlorine (though some of it is bound to CYA and is in "reserve" and not on the "front lines" so to speak) while Combined Chlorine is chlorine that is attached to organics or ammonia and is no longer active and may smell (chlorine attached to ammonia is called chloramine and smells bad).

For bringing down the TA it's the following sequence of steps:

1) Add acid to lower pH to 7.0

2) Aerate (run spa jets) and monitor the pH. When it gets to 7.2, add acid to lower the pH back to 7.0 and repeat this process and periodically measure the TA. It should be dropping. When the TA gets to where you want it (say 60), go to the next step.

3) When you reach your target TA level continue to aerate, but don't add any more acid. This will cause the pH to rise with no change in TA.

The reason this works is that aerating raises the pH with no change in TA while acid lowers both pH and TA so the combination just lowers the TA.

If you don't understand something, it's my fault, not yours. I'm the one who needs to be patient so don't be afraid to ask questions.

[ffde31]

Hi again,

wow, thanks for being so detailed. I am a detail person and it helps to have to the step by step. I received my Taylor Kit (k-2006) today and am anxious to run the numbers. It is pouring rain outside right now so it will have to be tested later. I will take all baseline measurements with my new kit first before doing any chemical manipulation. I am curious to see what my CYA measures in the tub, I tested right after I acheived normal levels, (after initial fill). That took me a day or so. I started out with a TA of about 360ppm. I think by like the 2nd or third day I had pretty good levels, just some fluctuation in the pH and chlorine depletion a couple times. I have a question...why would the dealer tell me I need to use Spa Shock, which is 58% dichlor, 3x a week? You think I should Not use non-chlorine shock with the ozonater? should I use the spa shock?? or just use the dichlor for now to get my CYA where it needs to be? Would I continue the bleach for sanitation?, dichlor? and/or shock? Do I need to shock weekly?..If I sound unsure, that's because I am....

I will be sure to post my numbers when I measure.

thanks again, I really appreciate your time.

[ffde31]

Okay, the rain let up so I was able to check my levels. Here they are:

.4ppm FC

.6ppm CC (this could possibly be .4 as well, it was close-maybe .5?)

pH = 7.7

TA = 100ppm

CYA = still under 30 - maybe bwtn 25 and 30?

Now I'm not sure what the normal level of chorine should be when it breaks it down this way. My old kit did total Chlorine, I guess, and I tried to keep it 1-3ppm. Is it the same with the Taylor? It looks like I do need to bring down my TA and pH the way you said earlier. I will work on that tomorrow as I won't be usuing it tonight and I suspect that will take a little time.

What do I need to take care of first? Should I work on lowering the TA? That 3 step process sound easy enough. With the TA of about 60ppm, will that help with my chlorine stability? Should I stay with the dichlor for now? My bleach is 6%, when we've added it we've usually added 2oz after each use-do you think this is enough once I get the TA down? I'm sure once I sit down and digest all this it'll make more sense to me.

I guess I have to accept that I'm going to use more chlorine with our heavy usuage. We can't use the bromine because our spa has the Eco-Pur filters.

So tonight, my plan is to add acid to bring down the pH and add 2t of dichlor for the chlorine level. Hopefully this will do okay, I'll mess with the acid more tomorrow and bring the TA down. I don't want my tub to go all night with so little chlorine.

I'll check in with you tomorrow.

[chem geek]

Relax and let's just take one thing at a time. There's no rush here.

First, you asked about Spa Shock which is Dichlor. You should absolutely, positively not use that in the frequency that they suggest. You will build up Cyanuric Acid (CYA) in your hot tub way too fast and this makes chlorine less effective as a disinfectant. There is a bacteria that causes hot tub itch that is more difficult to kill than most bacteria and the 20 ppm CYA with 4 ppm FC level that I'm getting you to will conservatively kill the bacteria that causes hot tub itch. Several (at least 3, possibly more) users on this forum had hot tub itch (literally) and all had high CYA levels. It seemed that after about 2 months of Dichlor usage, the CYA got to around 80 or higher and that's when the hot tub itch first appeared.

Because of your ozonator, you should not need to shock at all. You should be able to just use the bleach alone (after using Dichlor initially right after refilling the tub with new water every 3 months or so). In other words, the sequence is:

1) drain/refill hot tub with fresh water

2) add some chemicals to get TA up, but not too high (we'll determine how high later)

3) Use Dichlor for a week or as long as it takes to add the equivalent of 20 ppm FC which should result in around 18 ppm CYA

4) After that first week of Dichlor, switch to using bleach only.

5) Repeat the above every 3 months

With the drop-based (i.e. count the drops) FAS-DPD chlorine test, you used a 25 ml sample and you added 2 drops to get the color to turn from pink to colorless, then added the reagent to test for CC, the sample turned pink, and you added an additional 3 drops to get it to turn colorless. Did I get that right? I'm just checking because it is VERY surprising to see CCs in your hot tub given you have an ozonator. Perhaps in the second set of drops it was only 1 drop and you added 2+1=3 -- is that right? That would make more sense and means that you really have only 0.2 ppm CC or less (which is great).

The lower TA will have no affect on the chlorine stability. With your ozonator, you will have more chlorine loss than those without an ozonator and unfortunately there's really nothing you can do about that. The good news is that with the ozonator it is very likely you are killing virtually every bug in your spa. The main reason for the chlorine is 1) to kill bugs that come from you so they get killed long before they have to recirculate through the ozonator and 2) to kill bugs that are stuck in biofilms on spa surfaces and won't go through the ozonator at all. So the fact that your chlorine swings wildly, though not great, isn't terrible either.

2 ounces of 6% bleach in 425 gallons will only raise the FC by 2.3 ppm so that sounds right if the FC starts at 1 ppm, you add 2.3 to get to around 3 ppm, then lose 2 over a day/night to get back to 1 ppm. You're probably fine with this, but if you want to be a little more conservative you can try going between 3 ppm FC up to 5 ppm FC so that you average closer to 4. That will ensure that hot tub itch is killed even stuck to surfaces. This isn't critical since my numbers are conservative so if you're more comfortable with your 1-3 that should be fine (with the ozonator).

By the way, if you find the chlorine to smell when you first get into the tub, just remove the cover and let the tub air out for 5 minutes or so. That should help a lot.

[ffde31]

okay, I'll try to relax. I get your procedure on the new fill. To give you some history: On our initial fill, a week ago, I added per dealer instruction: 2 oz "stain and scale" and 5 oz "spa shock" after that my levels were:

Chlor: >5ppm

pH: 7.8

TA: 320ppm

CYA: <30ppm

I then added acid to bring my TA down to what it is now (around 100ppm). My pH had fluctuated btwn 7.5 and 7.8 and my chlorine is depleted daily-due to usuage I'm now sure of. Looking back at my log, I see that on 5/4 my TA was 60ppm, pH 7.2 and chlor was 2ppm. That sounds about perfect huh? Then I messed with it because I was told that the TA should be 80-150ppm. so I brought it up. Anyway, I will work with it tomorrow, I'll have time- no work tomorrow.

Thanks for all your guidance..you are very kind. I'll let you know...

[ffde31]

Well I have been working with the levels and have been able to get things into a pretty good range and hold them fairly steady.

The pH = 7.4, TA=80ppm (still want to get that down a little more) and FC varies btwn 2-3 ppm.

I have learned that adding about 3oz of 6% bleach keeps the FC pretty steady except when the pH starts creeping. I do have to adjust the pH with decreaser about every 5 days or so. I still want to do the procedure you outlined earlier-dropping the pH to 7.0 then up to 7.2 then back down to 7.0 to get the TA down a little more. But for now things seem pretty good.

I do have a question though. We are leaving on vacation on Friday- I am thinking I should just drop some spa shock in the tub and turn it on economy mode before leaving. Does that sound like the thing to do? Upon startup we added 5 oz spa shock, should I add this amount? We are leaving for a week.

I do appreciate all the guidance and sorry it took me so long to update.

thanks again