Nitro's Approach To Water Maintaince

[Nitro]

Basically you want to balance your water (i.e. adjust TA, pH and CH). Then give it a good shock (10 ppm FC) with Dichlor.

[drewskie]

Basically you want to balance your water (i.e. adjust TA, pH and CH). Then give it a good shock (10 ppm FC) with Dichlor.

So it would not be a good idea to use the tub tomorrow after filling?

[bart6453]

Basically you want to balance your water (i.e. adjust TA, pH and CH). Then give it a good shock (10 ppm FC) with Dichlor.

So it would not be a good idea to use the tub tomorrow after filling?

Just check your FC.....I find that my new water uses about 5ppm FC in the first day and then stabilizes out to to a lower Chlorine demand after that.

I dont like to go in my tub over 5ppm FC, some say you can go in up to 10ppm FC, I just think it's a bit too high for me.

Other than that, as long as your water is balanced, I wouldn't hesitate to jump in the next day.

[cporro]

i'm bit confused. had this same issue/question last time.

using nitro's method (thx!). i drained refilled, heated to 100F, brought calcium up to 160ppm, brought TA up to 80ppm.

but my ph is 8. my csi (pool calc) is 0.44. and i think chlorine is less effective at this ph.

i'm using a taylor 2006 (kit) and have done 2 tests confirming original data.

where did i go wrong?

thx

[chem geek]

Don't bring the TA to 80 ppm. It may need to be lower, say at 60 ppm, to get a more stable pH at around 7.7. You can use 50 ppm Borates (Proteam Gentle Spa) to get more pH stability at a low TA level. TA is a source of rising pH from the outgassing of carbon dioxide. Also realize that more aeration (longer running of spa jets, for example) increases that rate of outgassing.

As for chlorine effectiveness, with CYA in the water it doesn't become as ineffective as the traditional industry graph shows. A comparison in the traditional graph vs. the true graph (if you are interested) is shown in this post.

[EDIT] Also, are you saying that the pH is high even in the first week when using Dichlor or did this happen after switching to bleach? What brand of bleach are you using? 6% Clorox Regular has the least amount of excess lye in it. Off-brand bleaches almost all have more excess lye so would make the pH rise more requiring more acid addition. As QCD notes in his post below, your other water chemistry parameters are off as well; I don't know why you set your CH so high, for example. [END-EDIT]

[quantumchromodynamics]

brought calcium up to 160ppm, brought TA up to 80ppm.

but my ph is 8. my csi (pool calc) is 0.44. and i think chlorine is less effective at this ph.

where did i go wrong?

thx

Your pH, alkalinity and calcium are all too high. You should maintain a slightly negative CSI.

I recommend the following levels

pH 7.6 to 7.8

TA 40 to 80

Calcium 80 to 120

CSI -0.3 to -0.1

[cporro]

the spa has just been filled. basically first day. there is no chlor in there yet. but there will be today. i used safeway bleach before. always had a high ph.. i can try clorox this time.

i really thought the CH could be anywhere in that big range. 150-300. so i went up from 40 to 160. slight overshoot, was trying for 150.

so next time. keep CH lower, and test ph whilst increasing TA? that's where i get confused. to me it read like get CH in right range, test TA..then adjust it to around 80, then fine tune it. no mention of testing of ph at that point. using the pool calc a TA of 80 with my other levels should give me like 7.5 ph and a nice csi.

as things stand now should i add acid to bring ph down? once in a good place add gentle spa?

it seems impossible to hit the ph ideal range and the TA ideal range.

thx again.

[quantumchromodynamics]

The first thing you should balance is the Total Alkalinity. There is no "ideal" range for alkalinity. You balance it based on where it keeps the pH at the ideal level. If your pH is high, then you lower the alkalinity. If your pH is low, then you raise your alkalinity. If your pH is good then you leave the alkalinity alone, whatever it is.

Most people find that an alkalinity of 60 to 80 will work for them while they are using dichlor. Most people find that an alkalinity of 40 to 60 will work for them when they switch over to bleach. People with hotter water and more aeration will require a lower Total alkalinity than people who have cooler water and less aeration.

That takes care of your pH as well. Then you add borates from boric acid. Then you use dichlor for chlorination until the cyanuric acid reaches 30 ppm. Then you balance the calcium where it gives you a CSI of about -0.15.

Your CSI of over +0.3 will almost definitely start to cause scale unless you reduce it fairly quickly. I recommend that you use muriatic acid to keep the pH at about 7.5 until it stays there. It will stay there when your Total alkalinity reaches the correct level.

[quantumchromodynamics]

You will be in balance once your pH reaches about 7.5 to 7.6.

Also, note that the recommended ranges suggested by the Poolcalculator request the following information.

Use suggested goal levels from: Trouble Free Pool

Primary source of chlorine: Bleach

Pool surface: Fiberglass

I think that the suggested ranges are more for pools than spas.

I think that it might be helpful if the poolcalculator also asked if the water would be for a pool or spa. It does use temperature to calculate the correct CSI; however, it does not adjust the recommended ranges based on the temperature.

Hotter water causes more carbon dioxide to outgas faster than cooler water.

For your current water, I recommend the following levels:

pH 7.5 to 7.8

Total Alkalinity 70

Calcium 160 (Already there so we will work with it.)

Cyanuric acid 30

Borate 50

[chem geek]

QCD is absolutely correct. The "suggested ranges" in The Pool Calculator are for pools. However, if you enter in your true numbers into the calculator, including the hotter spa temperature, you will find that you can't have the CH be that high along with TA otherwise the saturation index will be too high (> 0). So if you just focus on the saturation index, then you'll get the desired result where you usually start by finding a TA and pH level where the pH is more stable (and where the pH isn't too high -- usually between 7.5 to 7.8, not 8.0), then set the CH so that the saturation index is a little less than 0.

The Pool Calculator should probably have a companion link called The Spa Calculator that is essentially the same except for the recommended ranges where the CH will be more like 100-150 ppm. I'll suggest that to Jason who wrote it.

[cporro]

The first thing you should balance is the Total Alkalinity. There is no "ideal" range for alkalinity. You balance it based on where it keeps the pH at the ideal level. If your pH is high, then you lower the alkalinity. If your pH is low, then you raise your alkalinity. If your pH is good then you leave the alkalinity alone, whatever it is

holy crap. i just had a breakthrough in group. thx. serious. that's the missing piece for me.

[cporro]

thx you guys. armed with new insite we'll see how it goes.

[kbaumann]

If you properly manage your spa water chemistry, especially the pH, Total Alkalinity (TA), and Calcium Hardness (CH), then you won't need any scale defense. That product would only be useful if your CH level in your fill water were extraordinarily high (> 300 ppm) since you will be lowering your TA level with the Dichlor-then-bleach system and the Borates will keep the pH from rising too quickly. The metal protector isn't needed unless you have metals in your fill water. Unless you are using well water, then I doubt you have many metals in your fill water. By metals, I mostly mean iron (there usually isn't copper in fill water).

Using ozone is a mixed bag. Ozone can consume chlorine so if you don't use the tub every day then the ozone can result in your needing to use more chlorine. If you use the tub every day and have higher bather load (longer soaks with more people), then the ozone can supplement the chlorine for oxidation so that you would use less chlorine. Generally speaking, ozone isn't ideal with using chlorine. It's generally better with bromine to reactivate bromide to bromine. For chlorine, an alternative or supplemental system that works well is Nature2 that can provide extra insurance if you don't maintain chlorine levels consistently, but this is not necessary and is extra cost.

So do you think that if I am using the Nature 2 system with MPS... and shocking with bleach to achieve 12ppm every two weeks with CYA at 30ppm... that I should unplug the ozonator? Why I ask is because with the spas I work on they have the circulating pump and ozone running nonstop... I am wondering if this is one reason the spa covers are wearing out so fast? And also will to much ozone hurt the jets as well? ~ Karl

[chem geek]

If the ozone is always on (except perhaps when someone is in the tub since the use of jets may turn off the ozonator), then that certainly could have a negative impact on hot tub covers and I seem to recall a dealer posting about that a while back. If you are using enough MPS, and you are periodically shocking with chlorine (bleach) then the ozonator shouldn't be needed. Others will have to tell you their experiences with different ozone systems running over different amounts of time.

[mikef135]

An excellent writeup! Just to note: the 7 ppm FC per person per hour guideline is for a 350 gallon tub. The other way to say it is that the guideline is 3-1/2 teaspoons of Dichlor or 5 fluid ounces of 6% bleach (e.g. Clorox regular unscented) or 7 teaspoons of MPS non-chlorine shock per person per hour -- that quantity of sanitizer is independent of tub size. This guideline is conservative for fairly hot tubs (near 104F) and as you point out the actual amount depends a lot on the cleanliness of the bathers, how much they sweat, what else they dump into the tub, etc.

I would also add that with the Dichlor then bleach method, even after adjusting TA, some may find the pH to rise too much, especially if they have an ozonator. The Borates will help slow the pH rise, but the same amount of acid will be needed to lower the pH back down to the desired range.

Richard

I bought a used 7'x7'x39.5" cal spa on craigslist and am planning to use this maintenance strategy after the decontamination process. I have the referenced Taylor kit on order. I suspect the tub is between 5-10 years old ... don't know for sure but based on what I have read online the original ozonator should be dead as they don't last that long. Any recommendations here?

1) unplug it so it isn't wasting power?

2) leave it plugged in? - maybe I am missing something here

3) buy a retrofit model for around $100?

4) get some of this MPS stuff instead/in addition?

Will an ozonator help as a "buffer" so the FC is less likely to drop to 0 should maintenance go lax for a few days? IE: there is a backup oxidizer still working in the background if a bleach dose is missed for example?

Thanks,

-Mike

[LAguy]

This is a great write up, but I am a complete newbie and it's very confusing. Had my spa a week and getting cloudy water and scum on the sides. I'm really overwhelmed because I have tested (with strips) and tried to keep things balanced. Ultra Management Water System (LA SPas). It has an ozinator and 24 hour pump. Using Chlorine method and have a mineral stick. Started with Metal Gone and have put in things like Enzyme, Defender and Bright and clear and Foam gone, and Renew. The thing should be sparkling.

The dealer said it is so easy. Just shock the system a few times a week and add a little chlorine a few times a week. Ummmm.... not so easy.

My calcium level is a little low, so maybe that is throwing everything off.

Also doesn't the ozone eat away the chlorine so what is the proper balance to maintain?

Pulling my hair out!

[chem geek]

This post is a shorter summary of the Dichlor-then-bleach method.

As for your specific situation, test strips are next to useless as they are not accurate. You should invest in a good test kit, the best being the Taylor K-2006.

It sounds like you did not start off doing a decontamination of your new spa and that is important to get rid of the oils/greases and biofilm in a wet-tested spa. You could use Spa System Flush instead of superchlorination, especially for a new spa.

Stop adding all of those extra chemicals to your spa. Also, if you are going to be using chlorine, then get rid of that mineral stick. If it's Nature2, then you could use MPS instead of chlorine as your primary sanitizer, but if you're going to be using chlorine then the mineral stick isn't providing extra value and just increases the risk of metal staining.

As for ozone, if you use the tub every day or two it should reduce chlorine demand by oxidizing some of the bather waste so that chlorine doesn't have to, but if you use the tub infrequently, once or twice a week or less, then ozone increases chlorine demand by oxidizing it to chlorate or reducing it to chloride salt.

[Hillbilly Hot Tub]

new spas have a lot of "goop" in them, not just from them being water tested, but the plastics have a lot of residue that leaves a gooey mess. We tell our customers to drain after the first month, and yes you will need a nature 2 stick again if you choose nature 2, plus filter cleaning is very important. Weekly with heavy use and with new tubs. you have added a lot of 'clarfiers/cleaners" and these can clog up the filter so its not doing its job right. it should be better after your first water change, and as chem geek said, if you are going to use nature 2, then follow the low chlorine recipe, its in the nature 2 box, otherwise your CYA level will get to high very quickly and you will have to drain again.

[ChemNewbie]

For example: On one day you test your FC and it's 1 ppm. You'll then add 5 ppm FC to bring it to 6. The next day you test FC and it's 3. You then add 3 ppm FC. You will do this until you add a total of 34 ppm FC to your tub using Dichlor. After that, you then switch to using bleach (Clorox Regular Unscented). Important: if you're not willing to test your tub everyday, at least for the first month or two, this method is not for you. I'd recommend another sanitation method

*********

I am new to this forum, and, as you can tell by my user name, new to the whole hot tub chemist thing. We had a Morgan spa for years, and just a few weeks ago, got a new Clearwater Spa. I have decided to take over the water maintenance, as my husband is more of a, "Ah, it's fine, it doesn't look bad," kinda guy. So, we've had some problems getting the water levels right, and have emptied refilled it twice using the limited info our dealer gave us. We're still struggling, so I started some research and voila! Here I am, wishing Nitro and Chem Geek were my neighbors so they could help me make sense of the mess I've got going.

At the recommendation of the dealer, we have a Sundance Sun Purity Mineral Purifier cartridge in the filter basket. He said we wouldn't need any other chemicals, but that makes me a bit uncomfortable. So I bought a six way test kit and started my chemistry class. Armed with a laminated copy of the test procedures (I knew I would drop it in the tub...and I did), and the many bottles and tubes inside the kit, I started testing. Nothing was right. Nothing. The chlorine level was so low, it didn't even register. I added Di-Chlor as per the instructions on the bottle, and upon the next test, got a water sample that was so orange, it was arguably red. I called the dealer, who took the opportunity to say "I told you so", and proceeded to lecture me about the fact that no other chemicals were to be used. I drained it, refilled it, got the numbers on the test kit to pretty much in range, washed all of our suits in a load with nothing but hot water and a cup of vinegar, and enjoyed a clear tub for approximately 24 hours. Then a dense foam started forming that contained a very nasty brownish/yellow slime that crusted on the edge of the tub. Nasty. I shocked it, checked the levels, and found that the chlorine again was essentially non-existent. pH levels seemed to be fine, though. Added di-chlor at recommended levels, got a too-high reading, let it sit in the sun for an hour, retested, found the levels within range, and figured I was good. However, this routine has continued to repeat itself daily for two weeks now. The chlorine levels keep plummeting, and the slime and foam keep forming. The pH levels read fine, but now that I've read through your Water Maintenance information, I realize that doesn't mean much. So I'm about to embark on your Decontamination process, and then want to refill and maintain according to your recommendations. I was doing fine with understanding everything until I reached the 'Sanitation' section. I'm lost with the calculating CYA using Di-chlor measurements and FC levels. I realize that puts me in the 'not the sharpest tool in the shed' category, but it is what it is. Perhaps I need to choose a different sanitation method? Anyway, any advice you might be willing to share in regards to my endeavor for a clean, healthy hot tub would be greatly appreciated.

[chem geek]

Since this is a new spa, I would first get Ahh-Some® as that will clean out any greases/oils leftover from manufacturing as well as any biofilms. You would use this before changing your water.

For every 10 ppm Free Chlorine (FC) added by Dichlor, it also increases Cyanuric Acid (CYA) by 9 ppm. So after a water change you would use Dichlor until you've cumulatively added around 33 ppm FC and then you'd switch to using bleach. Once a month you could use Dichlor for a day. You can use PoolMath to calculate dosages.

You should not let the disinfectant level get to zero in the spa. You need to add enough chlorine after your soak so that you still have a measurable FC (say 1-2 ppm) just before your next soak. If you don't soak every day or two, then you will likely need to add more chlorine in between soaks. If you use an ozonator, then ozone will react with chlorine so while it will lower your chlorine dosage after each soak it will increase the amount you need to add in between soaks. So usually with an ozonator it will work well with chlorine if you use the spa every day or two but will increase your maintenance if you only use the spa infrequently, say only on weekends.

[d54son]

Thank you for you time in writing this column . It is more info than I have ever gotten from my dealer. this will help my headache .

[CarolCPalmer]

The blog is really informative and useful. I often struggle with pool maintenance. Writeup like this would definitely help us more responsible pool owners

[cpd5215]

Hello all,

I have been reading these threads for days and have learned a great deal about water chemistry and sanitation. Thanks you to all of you that are willing to help us folks that don't have a lot of knowledge in this department. I really appreciate it!

I have had a brand new hot tub (395 gallons) for the past two weeks that I have been struggling with. It is bromine based(Spa Frog with bromine and mineral), but after reading this thread and other, I have decided to switch to the dichlor and bleach method. I have been instructed to decon my tub with Ahh-some as it seems I have some "gunk" even though its new. I now know, new does not mean clean. I also got a Taylor 2106 already for my bromine and borate strips. Ahh-some arrives tomorrow, so tomorrow is the day to decon and make the switch. I filled a container with some water out of the hose(pre-filter attached) and tested it today to get an idea of where I might stand. Here and the levels:

pH-it was below the 7.0 on the vial. I added 4 drops to increase and it rose to 7.6

TA-60

CH-125

I have 20 Mule Borax here and would like to add that to the equation as it seems most of you recommend it.

When I fill the tub tomorrow, if the numbers look the same, whats my best course of action. It seems my water from the hose doesn't need much adjusting as I have played with the pool calculator but I would like to ask the experts opinion on which chemicals I should add to get a good CSI.

Should I add the borates to 50ppm immediately after filing and before balancing so I can see what effect that has on pH and TA?

I don't know much other than what I read about the test kits. I think mine will still read chlorine right? Do I need something else to test CYA, or just use test strips? Any other equipment I might need to get to use with the kit I already have?

Any recommendations would be greatly appreciated. I am very exited to get this started. I love playing "chemist" now. Bye Bye test strips!

[apostlej2015]

After your fill, measure pH and TA. If the number you measured out of the hose stay consistent after you fill the tub, you need to run the jets with air (aerate) till the pH is 7.4. Then add the borates. If you add the borates before balancing, it will require more TA up/down to stabilize. Note that the aeration will take a couple hours to get from 7 to 7.4. Run it an hour...measure. Repeat till 7.4.

Do not test your CYA. Just add dichlor per the calculator and record the resulting FC*0.9 and keep adding dichor till you've added 35-40PPM CYA. You can then go get your water tested 4 free to see if CYA is perfect (it will be if you measure based on poolcalc and do not keep the spa water exposed to the sun for a long period of time).

I say don't test your CYA...record based on dichlor dispensed, because the taylor kit is worthless if your CYA is below 40PPM (readings less than this fill the vial). Plus you will useup that CYA solution real fast. Once you have switched to bleach, note that your CYA WILL DEPLETE in a month. Mine went from 40PPM to less than 10 in three weeks. Just shock or swap dichlor for bleach and rerecord till your levels are back.

[Ottawa Grandma]

Hi Everyone,

Just bought a hot tub July 27. I'm getting a bit frustrated. Went back to the lab twice at the store. PH: 7.8, T.A: 124 ppm, CH: 105 ppm, CYA 3 ppm - but F.C. is 0.09!! Can't seem to get the chlorine up. Using Lithium. Everytime I shock it and re-test it, it still shows zero on my strip.

Any advise?