Dichlor/bleach Questions....confusion

[cocoabailey]

Hi all,

I am new to this forum and have been doing lots of reading over the last few weeks prior to finally registering. I am really interested in the trying the Dichlor Bleach method. I have a few questions I'd like to clear up prior to starting. Perhaps you may able to provide some guidance?

Do you have to test (measure) the CYA to employ this method, or will adding 2 teaspoons a day of Dichlor until around eleven tsp has been added or 7 days, prior to the switch to bleach suffice?

What percentage of Dichlor is being referred to in this forum? Is is 99%, 52%, 75%? I currently have a product which contains 52.7% of dichlor and 14.6 sodium bromide. Will this work for the initial build up of CYA, or d I have to switch to another product? If so, I am in Canada and would love it if anyone could provide a distributor that ships to Canada.

I will be going away for a few weeks. If no one is using the spa, does it still have to be treated weekly? What if the water temp is turned down.

That's it for now. Thanking you advance for your input. This site truly does contain a wealth of knowledge! Thanks again.

T

[Nitro]

Hello, and welcome to the forum.

The Dichlor we refer to has an Active Chlorine Content of ~55% (Chem Geek can confirm this). However, if the stuff you have has Sodium Bromide in it, you can't use it in you tub if you plan to stay a Chlorine tub. Once you introduce Bromine, you can't get rid of it until your next water change. Therefore you need get something else. I'm not an expert on Bromine, so maybe someone else can weigh in on this.

As far as CYA, you don't need to measure it if you keep track of how much Dichlor you use. For every 10ppm Free Chlorine (FC) you add to your tub, you also add 9ppm CYA. That means you want to add ~25ppm FC using Dichlor before you switch to bleach. In a 350Gal tub that's ~2oz Dichlor. That may take one or two weeks, depending on how much you use the tub.

As far as leaving your tub, I don't recommend leaving it much longer than a week, without adding Chlorine. If you're going to be gone longer than a week you may want to find someone that could add some Chlorine for you. A shock to 10ppm once a week is fine. Another option is to use Nature2 mineral sticks. That may prolong the time between shocks. I'm not an expert on that system, so maybe someone else can weigh in.

However, keep this in mind. When you first fill your tub your Chlorine Demand (CD) should be ~25% (nice and low). That means your tub will use 25% of the FC everyday, with no use. If you shock your tub to ~10ppm, you can go a week without FC dropping below 1ppm. On the other hand, if you've been using your tub a lot and haven't been adding enough Chlorine to keep up, your CD will increase. For instance, if your CD is 50% (i.e. every day your FC drops in half), you can only go a few days after a shock to 10ppm. So the key is to keep your CD low, and your tub won't be using it up too fast. Here's an article I wrote about it.

Hope that helps.

[chem geek]

Hi all,

I am new to this forum and have been doing lots of reading over the last few weeks prior to finally registering. I am really interested in the trying the Dichlor Bleach method. I have a few questions I'd like to clear up prior to starting. Perhaps you may able to provide some guidance?

Do you have to test (measure) the CYA to employ this method, or will adding 2 teaspoons a day of Dichlor until around eleven tsp has been added or 7 days, prior to the switch to bleach suffice?

What percentage of Dichlor is being referred to in this forum? Is is 99%, 52%, 75%? I currently have a product which contains 52.7% of dichlor and 14.6 sodium bromide. Will this work for the initial build up of CYA, or d I have to switch to another product? If so, I am in Canada and would love it if anyone could provide a distributor that ships to Canada.

I will be going away for a few weeks. If no one is using the spa, does it still have to be treated weekly? What if the water temp is turned down.

That's it for now. Thanking you advance for your input. This site truly does contain a wealth of knowledge! Thanks again.

T

The most common Dichlor is the dihydrate form and it is often nearly 100% pure. The 55% (sometimes quotes between 52% and 55%) is the % Available Chlorine for that purity of product. An ingredients list, which is what it sounds like you are reading, has the percentage weight of product so that 52.7% is probably a weight percent of Dichlor so is very far away from being pure. Also, as was pointed out by Nitro, the 14.6% sodium bromide essentially turns your spa into a bromine spa since the chlorine will activate the bromide to bromine (and use up the chlorine to chloride -- salt). So you should only use the product you have if you want a bromine spa, not a chlorine spa.

You should have no problem getting nearly pure Dichlor in Canada since all the major manufacturers/distributors have such products. For example, you should be able to get SpaGuard Chlorinated Concentrate or SpaGuard Stabilized Chlorinating Granules (they seem the same to me according to the MSDS -- not sure why they have two different products), GLB Rendevous Chlorinating Concentrate Granular, Leisure Time Spa 56 Chlorinating Granules (this product may not be pure), Robarb Sani-Spa (this product may not be pure), HTH Chlorinating Granules.

If you are regularly going to be gone for a week or more, then getting a silver ionization system such as Nature2 (N2) will help to prevent uncontrolled bacterial growth even if the chlorine gets too low.

Richard

[cocoabailey]

Hi all,

I am new to this forum and have been doing lots of reading over the last few weeks prior to finally registering. I am really interested in the trying the Dichlor Bleach method. I have a few questions I'd like to clear up prior to starting. Perhaps you may able to provide some guidance?

Do you have to test (measure) the CYA to employ this method, or will adding 2 teaspoons a day of Dichlor until around eleven tsp has been added or 7 days, prior to the switch to bleach suffice?

What percentage of Dichlor is being referred to in this forum? Is is 99%, 52%, 75%? I currently have a product which contains 52.7% of dichlor and 14.6 sodium bromide. Will this work for the initial build up of CYA, or d I have to switch to another product? If so, I am in Canada and would love it if anyone could provide a distributor that ships to Canada.

I will be going away for a few weeks. If no one is using the spa, does it still have to be treated weekly? What if the water temp is turned down.

That's it for now. Thanking you advance for your input. This site truly does contain a wealth of knowledge! Thanks again.

T

The most common Dichlor is the dihydrate form and it is often nearly 100% pure. The 55% (sometimes quotes between 52% and 55%) is the % Available Chlorine for that purity of product. An ingredients list, which is what it sounds like you are reading, has the percentage weight of product so that 52.7% is probably a weight percent of Dichlor so is very far away from being pure. Also, as was pointed out by Nitro, the 14.6% sodium bromide essentially turns your spa into a bromine spa since the chlorine will activate the bromide to bromine (and use up the chlorine to chloride -- salt). So you should only use the product you have if you want a bromine spa, not a chlorine spa.

You should have no problem getting nearly pure Dichlor in Canada since all the major manufacturers/distributors have such products. For example, you should be able to get SpaGuard Chlorinated Concentrate or SpaGuard Stabilized Chlorinating Granules (they seem the same to me according to the MSDS -- not sure why they have two different products), GLB Rendevous Chlorinating Concentrate Granular, Leisure Time Spa 56 Chlorinating Granules (this product may not be pure), Robarb Sani-Spa (this product may not be pure), HTH Chlorinating Granules.

If you are regularly going to be gone for a week or more, then getting a silver ionization system such as Nature2 (N2) will help to prevent uncontrolled bacterial growth even if the chlorine gets too low.

Richard

Richard and Nitro,

Thanks for the info. You guys are great, I was expecting a long wait, but the quick replies are fabulous. I neglected to mention that I am currently using a bromine system with the floater. One of my uncles mentioned he had been using bleach for a long time, so I looked into and found this site.

I looked into the N2 system a little but I really don't know enough to comment at this time, more research for me.

Where I am switching from bromine to chlorine, is there any special procedures I should follow when swapping the water? Do you have to leave the cover open after you add the bleach? What if you use a bubble/foam cover under your actual hot tub cover? I haven't heard about those before today, but they sound pretty neat.

Thanks again for the info.

T

[Nitro]

Think of the N2 System as being a "safety net". If you leave the tub for weeks at a time, you can add the N2 system to help keep the tub safe. I'd still recommend finding a friend to add bleach once a week. While you are at home using the tub, I would follow the Dichlor/Bleach method described here.

As far as adding bleach. I usually leave the cover off for 20min if adding more than 6ppm FC at a time (i.e. after using the tub, or shocking). If I'm just adding a maintenance dose (6ppm or less), I close it up after adding it. Bubble foam, covers etc. should not be effected by bleach anymore than Dichlor, IF you have CYA (20-30ppm) in the tub.

[cocoabailey]

Think of the N2 System as being a "safety net". If you leave the tub for weeks at a time, you can add the N2 system to help keep the tub safe. I'd still recommend finding a friend to add bleach once a week. While you are at home using the tub, I would follow the Dichlor/Bleach method described here.

As far as adding bleach. I usually leave the cover off for 20min if adding more than 6ppm FC at a time (i.e. after using the tub, or shocking). If I'm just adding a maintenance dose (6ppm or less), I close it up after adding it. Bubble foam, covers etc. should not be effected by bleach anymore than Dichlor, IF you have CYA (20-30ppm) in the tub.

Thanks again. Sorry to be a flurry of questions here, but the more I read, the more questions

I seem to have...I guess that is what learning is all about.

I have a lot of jets, will that cause a big aeration issue (raise in ph)?

In my tubs manual the recommended TA is 120-140 ppm, yet 80 ppm seems to be the desired TA with the bleach system....will this hurt the tub?

Borates - where can you buy these, or can you recommend a brand? Do you need them when using the bleach method...I must admit I am kind of concerned on the PH bounce, yet I would really like to give this a go.

Dry acid - sodium bisulfate (I think) can you buy this at a spa store?

Acid - do you recommenced against using against liquid acid to lower TA ?

Can I sub MPS into this system, use (MPS/Bleach/and Dichlor) and do you have any thoughts on doing so?

Is the a formula for calculating how much chlorine you have to add?

Can you still use clear blue or scented products with the tub?

Sorry for all the questions, I am just trying to get the last few facts together before I switch.

Thanks again for the insight it is much appreciated!!

T

[Nitro]

Thanks again. Sorry to be a flurry of questions here, but the more I read, the more questions

I seem to have...I guess that is what learning is all about.

No problem. This may seem like a lot to learn, but once you learn it, it's very easy.

I have a lot of jets, will that cause a big aeration issue (raise in ph)?

In my tubs manual the recommended TA is 120-140 ppm, yet 80 ppm seems to be the desired TA with the bleach system....will this hurt the tub?

It won't hurt the tub as long as your pH is in range and your SI is near zero. My TA is 60ppm, pH is 7.6-7.8 and my CH is 200ppm. No problems.

Borates - where can you buy these, or can you recommend a brand? Do you need them when using the bleach method...I must admit I am kind of concerned on the PH bounce, yet I would really like to give this a go.

The easiest way to add Borates is a product called Gentle Spa found here. Don't worry about pH bounce. It's a non-issue.

Dry acid - sodium bisulfate (I think) can you buy this at a spa store?

Acid - do you recommenced against using against liquid acid to lower TA?

You can get Dry Acid (aka pH Decreaser) at the spa store. I wouldn't use liquid acid (Muratic Acid). It's a little dangerous to work with. Once you get your TA in line, you won't be adding much acid.

Can I sub MPS into this system, use (MPS/Bleach/and Dichlor) and do you have any thoughts on doing so?

If you have high bather loads, you can use MPS to help oxidize bather waste. It will also lower CD. However, IMO, I wouldn't use MPS at first. I would just get the hang of using bleach. Then if you find it difficult to keep up (i.e. high bather loads) you can use MPS. Without high bather loads MPS isn't really needed.

Is the a formula for calculating how much chlorine you have to add?

ThePoolCalculator will calculate everything for you.

Can you still use clear blue or scented products with the tub?

Not sure what Clear Blue is, but you can use scented products. HOWEVER, just remember this: EVERYTHING YOU PUT IN YOUR TUB, STAYS IN YOUR TUB UNTIL YOU CHANGE THE WATER. That means the less you put in the better. I would not use anything except the bare minimum.

Sorry for all the questions, I am just trying to get the last few facts together before I switch.

No problem. Ahain, it's very easy once you get the hang of it. You don't need to use a bunch of chemicals. And best of all, you'll never have water problems.

[Hillbilly Hot Tub]

I would like to note, Richard, you list HTH chlorinating granuals on your list. The HTH product sold at places like walmart is not dichlor....it is calcium hypochlor.....as their shock is also (marketing ploy since 1 costs much more than the other)

[cocoabailey]

I would like to note, Richard, you list HTH chlorinating granuals on your list. The HTH product sold at places like walmart is not dichlor....it is calcium hypochlor.....as their shock is also (marketing ploy since 1 costs much more than the other)

Again thanks for all the info, and very speedy to boot. You guys rock! I am almost ready to make the switch. I was speaking at a spa place today, ad they sell the dichlor I am looking for 62% FC I believe. One question cropped up though...can you use dichlor that is sold for pools in your tub? The sales person said you could but the pool stuff is alot harder on your spa equipment?? Yet even though they have exactly the same chemical data??? Sounds like a sale gimmick to me, the pool stuff is much cheaper and comes in a larger quantity as well. Any thoughts with regard to this?

Will the pool calculator tell me exactly how much chorine to add?

Is there any special procedures to follow for adding borates? Is there a certain time to add?

Baking soda is supposed to increase TA but does it increase PH as well like it does when using products like resist (for increasing alkalinity)?

Before I dump my water I was thinking about dumping in some pipe/tub cleaner, either natural or chemical in nature (chem ones are cheaper but supposedly not as effective). Do these products actually do as advertised and is it worth it?

Thanks again for all the info gents it really is appreciated!! My apologies in advance for the 10000 questions, hopefully I can help others out in the future once I get it all straight.!

T

[Nitro]

Again thanks for all the info, and very speedy to boot. You guys rock! I am almost ready to make the switch. I was speaking at a spa place today, ad they sell the dichlor I am looking for 62% FC I believe. One question cropped up though...can you use dichlor that is sold for pools in your tub? The sales person said you could but the pool stuff is alot harder on your spa equipment?? Yet even though they have exactly the same chemical data??? Sounds like a sale gimmick to me, the pool stuff is much cheaper and comes in a larger quantity as well. Any thoughts with regard to this?

Any Dichlor is fine to use in your spa. I don't know why the salesman would say otherwise, unless he was referring to Trichlor, which is not the same as Dichlor.

Will the pool calculator tell me exactly how much chorine to add?

Yes, you plug the starting amount in the left column, and the ending amount in the right. It then calculates how much you need to add. It's pretty self-explainatory. Have you checked it out?

Is there any special procedures to follow for adding borates? Is there a certain time to add?

Just add it after you get your water balanced.

Baking soda is supposed to increase TA but does it increase PH as well like it does when using products like resist (for increasing alkalinity)?

Baking Soda will not increase pH very much, which makes it ideal for adjust TA without effecting pH.

Before I dump my water I was thinking about dumping in some pipe/tub cleaner, either natural or chemical in nature (chem ones are cheaper but supposedly not as effective). Do these products actually do as advertised and is it worth it?

I use them and they seem to work, but the jury is still out of whether it's worth it.

[cocoabailey]

Again thanks for all the info, and very speedy to boot. You guys rock! I am almost ready to make the switch. I was speaking at a spa place today, ad they sell the dichlor I am looking for 62% FC I believe. One question cropped up though...can you use dichlor that is sold for pools in your tub? The sales person said you could but the pool stuff is alot harder on your spa equipment?? Yet even though they have exactly the same chemical data??? Sounds like a sale gimmick to me, the pool stuff is much cheaper and comes in a larger quantity as well. Any thoughts with regard to this?

Any Dichlor is fine to use in your spa. I don't know why the salesman would say otherwise, unless he was referring to Trichlor, which is not the same as Dichlor.

Will the pool calculator tell me exactly how much chorine to add?

Yes, you plug the starting amount in the left column, and the ending amount in the right. It then calculates how much you need to add. It's pretty self-explainatory. Have you checked it out?

Is there any special procedures to follow for adding borates? Is there a certain time to add?

Just add it after you get your water balanced.

Baking soda is supposed to increase TA but does it increase PH as well like it does when using products like resist (for increasing alkalinity)?

Baking Soda will not increase pH very much, which makes it ideal for adjust TA without effecting pH.

Before I dump my water I was thinking about dumping in some pipe/tub cleaner, either natural or chemical in nature (chem ones are cheaper but supposedly not as effective). Do these products actually do as advertised and is it worth it?

I use them and they seem to work, but the jury is still out of whether it's worth it.

Many thanks again. This is all coming together now. I found a post from waterbear last night that stated the same facts that dichlor is dichlor.

I have two questions I am not sure of the answers before I begin :

1) exactly what type of bleach can you use? I was in a store today and all the brands I looked at had a concentration of 6% sodium hypochlorite, will this work? I remember reading something about certain brands have excess fillers like lye?

2)can you use the tub during the initial dchlor phase, and if so do you have to increase the amount for increased use?

Again, thanks for all the input it truly is appreciated.

[Nitro]

Many thanks again. This is all coming together now. I found a post from waterbear last night that stated the same facts that dichlor is dichlor.

I have two questions I am not sure of the answers before I begin :

1) exactly what type of bleach can you use? I was in a store today and all the brands I looked at had a concentration of 6% sodium hypochlorite, will this work? I remember reading something about certain brands have excess fillers like lye?

Here in the States we use Regular Unscented Clorox bleach. However, in Canada the brand is called Purox. Chem Geek can give you details of the differences between bleaches.

2)can you use the tub during the initial dchlor phase, and if so do you have to increase the amount for increased use?

Sure, just don't get in with FC over 10ppm. Thats a little too strong. I'd wait until it's under 8ppm. Also, I recommend measureing your Baseline Chlorine Demand (CD) as described here. Just shock the first day and measure FC. Don't use the tub. Then wait 24 hours and measure FC again. CD = 1 - [2nd FC measurement] / [1st FC measurement]

[chem geek]

I would like to note, Richard, you list HTH chlorinating granuals on your list. The HTH product sold at places like walmart is not dichlor....it is calcium hypochlor.....as their shock is also (marketing ploy since 1 costs much more than the other)

Thanks for catching that. I meant to link to the HTH Spa Chlorinating Granules which is Dichlor. The one I linked to above was apparently the pool product which is Cal-Hypo.

[chem geek]

Many thanks again. This is all coming together now. I found a post from waterbear last night that stated the same facts that dichlor is dichlor.

I have two questions I am not sure of the answers before I begin :

1) exactly what type of bleach can you use? I was in a store today and all the brands I looked at had a concentration of 6% sodium hypochlorite, will this work? I remember reading something about certain brands have excess fillers like lye?

Here in the States we use Regular Unscented Clorox bleach. However, in Canada the brand is called Purox. Chem Geek can give you details of the differences between bleaches.

Usually, the less expensive off-brand bleaches are the ones with more excess lye and that would tend to raise the pH more. If you find a datasheet on them, then look at the pH. For 6% bleach, the pH should be around 11.5 (Clorox Regular is 11.4) and if it's 12.5 then this will tend to raise the pH too much. For 12.5% chlorinating liquid, it is more common to see this with a pH of 12.5 and that's OK -- it will raise the pH somewhat, but not too much. Purox is probably like that.

Don't forget that once you switch to bleach, you may find the pH rise due to carbon dioxide outgassing from your spa. You'll want to keep the TA lower to minimize that problem and you can use 50 ppm Borates in your spa as a further pH buffer, especially if you need to get the TA very low (say, to 50-60 or so) if you have a strong pH rise tendency (such as with an ozonator).

Richard

[cocoabailey]

Many thanks again. This is all coming together now. I found a post from waterbear last night that stated the same facts that dichlor is dichlor.

I have two questions I am not sure of the answers before I begin :

1) exactly what type of bleach can you use? I was in a store today and all the brands I looked at had a concentration of 6% sodium hypochlorite, will this work? I remember reading something about certain brands have excess fillers like lye?

Here in the States we use Regular Unscented Clorox bleach. However, in Canada the brand is called Purox. Chem Geek can give you details of the differences between bleaches.

Usually, the less expensive off-brand bleaches are the ones with more excess lye and that would tend to raise the pH more. If you find a datasheet on them, then look at the pH. For 6% bleach, the pH should be around 11.5 (Clorox Regular is 11.4) and if it's 12.5 then this will tend to raise the pH too much. For 12.5% chlorinating liquid, it is more common to see this with a pH of 12.5 and that's OK -- it will raise the pH somewhat, but not too much. Purox is probably like that.

especially if you need to get the TA very low (say, to 50-60 or so) if you have a strong pH rise tendency (such as with an ozonator).

Richard

Thanks again guys. I think I might have a hard time finding the right bleach though. JAVEX is the big seller here now, and according to their data sheet the ph is 12 -13...so too high. CLOROX bought out JAVEX back in 2006. I haven't had any luck finding PUROX as of yet, but I'll keep looking. If you have any ideas please do tell.

Thanks for the tips on the Borates, the pool cal should help me find the exact amount to get

to 50 ppm.

I do have an ozonator, but as you said as long as the TA is low that shouldn't be to big a deal.

I'll keep ypu posted. Thanks again!

T

[chem geek]

If the Javex is like this stuff, then it's 5.25% bleach with a pH of 12.5-13 which is pretty high. It's not a disaster, but it does mean that even keeping the TA low won't stop the pH from rising. Basically, if your TA is 60 ppm and CYA 30 ppm, then the pH would rise from 7.5 to 7.76 after cumulatively using around 23 ppm Free Chlorine (FC). At 4 ppm FC per day typical usage, that's about 5-6 days. It could be a little higher pH rise than this if the pH is closer to 13 than 12.5, but you get the idea. You can add acid regularly to compensate, but you are right that it would be better to find some better bleach or chlorinating liquid if you can.

Richard

[Hillbilly Hot Tub]

I would like to note, Richard, you list HTH chlorinating granuals on your list. The HTH product sold at places like walmart is not dichlor....it is calcium hypochlor.....as their shock is also (marketing ploy since 1 costs much more than the other)

Thanks for catching that. I meant to link to the HTH Spa Chlorinating Granules which is Dichlor. The one I linked to above was apparently the pool product which is Cal-Hypo.

All HTH Spa chlorinating granuales that I have seen, in Walmart, hardware stores ect has been Calcium Hypochlor, as is their spa shock. I have not seen di-chlor under the HTH name in over a year.

We sell Arch products and talked with our rep and showed him that the chlorine and shock were both actuaally calcium hypo, no difference although the price was different and that calcium hypo is not to be used in spas. I was told to meet the price points of these big box stores, that was what they did. Calcium hypo is the cheapest. If you look at their bags of pool chemicals, although labeled for vinaly pools, another as super shock, another as something else, they are all calcium hypochlor....

Nice box store marketing. For consumers out there....make sure to read the label and learn your chemicals names and percentages if you purchase from box stores....

Go to this link from the same website you are using, pull up the picture of the spa shock and read it....these are the new bottle designs and you can read what this one says...

http://www.acehardwareoutlet.com/(mgdg22v0...spx?SKU=8198236

[chem geek]

That's really weird, but you're absolutely right I do see the Cal-Hypo in the ingredients. This link refers to HTH Chlorinating Granules with a description that says "also contains cyanuric acid, which stabilizes your chlorine level". However, this link clearly shows Cal-Hypo in the ingredients of HTH Spa Chlorinating Sanitizer. So maybe that description that said it had cyanuric acid is wrong or they changed the product.

So, bottom line, assume that HTH is Cal-Hypo and not Dichlor (or read the ingredients label, if you can) so generally do not use it in a spa unless your CH is very low and you don't mind increasing it using this product. For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by 7 ppm.

Thanks again,

Richard

[cocoabailey]

If the Javex is like this stuff, then it's 5.25% bleach with a pH of 12.5-13 which is pretty high. It's not a disaster, but it does mean that even keeping the TA low won't stop the pH from rising. Basically, if your TA is 60 ppm and CYA 30 ppm, then the pH would rise from 7.5 to 7.76 after cumulatively using around 23 ppm Free Chlorine (FC). At 4 ppm FC per day typical usage, that's about 5-6 days. It could be a little higher pH rise than this if the pH is closer to 13 than 12.5, but you get the idea. You can add acid regularly to compensate, but you are right that it would be better to find some better bleach or chlorinating liquid if you can.

Richard

Hi there again, thanks for all the info, once again. I think I figured out why I can't find the Purox at Canadian Tire. I was looking under bleach, when it is actually liquid chlorine, or at least that is how it is listed in the store....even if they are the same thing. I spoke with the customer service department and they sent me the MSDS. Under Sodium hypochloride it says 7-13, and the PH is 12.5 -13. Will this work?

Thanks again,

T

[chem geek]

Under Sodium hypochloride it says 7-13, and the PH is 12.5 -13. Will this work?

Yes, this will work and is fine. The ranges listed are typical of chlorinating liquid. Usually, it's 10% or 12.5% with a pH around 12.5. You may need to experiment a little measuring the FC after you've added chlorine since apparently they don't commit to a specific strength and instead give you a broad range. Perhaps ingredients listed on the bottle are more specific about the sodium hypochlorite concentration.

Chlorinating liquid and bleach are the same except for strength.

[cocoabailey]

Under Sodium hypochloride it says 7-13, and the PH is 12.5 -13. Will this work?

Yes, this will work and is fine. The ranges listed are typical of chlorinating liquid. Usually, it's 10% or 12.5% with a pH around 12.5. You may need to experiment a little measuring the FC after you've added chlorine since apparently they don't commit to a specific strength and instead give you a broad range. Perhaps ingredients listed on the bottle are more specific about the sodium hypochlorite concentration.

Chlorinating liquid and bleach are the same except for strength.

Great, I have to pick some up tomorow, so I'll take a look on the bottle then. Just giving the spa it's pre drain treatment....back to borates for a second. The pool calculator say I should add 26 oz of borates to get the desired reading of 30-50, but it also says I'll haveto add 13oz of acid to drop the ph back down. Is this accurate, I thought the borates stabilized the Ph?

T

[chem geek]

It depends on your source of Borates. The Pool Calculator is referring to using 20 Mule Team Borax which will raise the pH a lot. If you instead use a product like ProTeam Gentle Spa, then this is pH neutral so you won't need to add any acid. It's a lot easier to add this way, though is more expensive (but a one-time addition per drain/refill). If you do use 20 Mule Team Borax plus acid, you can mix this in a bucket of spa water so that you don't cause big swings of pH in the spa adding them separately.

I'd go with 50 ppm Borates rather than 30 ppm. In a spa with the Dichlor-then-bleach method, you really want to have some decent pH buffering. Also note that you want to get your TA lowered as well. There are pros and cons for doing this before vs. after adding Borates -- not enough people have done it each way to know which is best. If you lower TA before adding Borates, then you'll find the pH swinging more during the TA lowering procedure, while after adding Borates it will take a lot of acid to get the pH lower for the procedure and a lot of aeration to bring the pH back up when you are done. My hunch is that it's easier to lower the TA before adding the Borates for that reason.

Richard

[cocoabailey]

It depends on your source of Borates. The Pool Calculator is referring to using 20 Mule Team Borax which will raise the pH a lot. If you instead use a product like ProTeam Gentle Spa, then this is pH neutral so you won't need to add any acid. It's a lot easier to add this way, though is more expensive (but a one-time addition per drain/refill). If you do use 20 Mule Team Borax plus acid, you can mix this in a bucket of spa water so that you don't cause big swings of pH in the spa adding them separately.

I'd go with 50 ppm Borates rather than 30 ppm. In a spa with the Dichlor-then-bleach method, you really want to have some decent pH buffering. Also note that you want to get your TA lowered as well. There are pros and cons for doing this before vs. after adding Borates -- not enough people have done it each way to know which is best. If you lower TA before adding Borates, then you'll find the pH swinging more during the TA lowering procedure, while after adding Borates it will take a lot of acid to get the pH lower for the procedure and a lot of aeration to bring the pH back up when you are done. My hunch is that it's easier to lower the TA before adding the Borates for that reason.

Richard

Interesting Richard. I planning on using borates which would be used for a pool. Do you see any problems doing that? I figured it would be the same as with the Dichlor that you could use either pool or spa, as they are exactly te same chemical....except the price is much lower. I have an old container of Soft (borates) for SPAs, the instructions on that bottle say to add 150g per 1000L on the initial fill and then 50g /1000L a week.....am I understanding you correctly that you only have to add them one? If so, 7kg is going to last for a very long time What dosage do you suggest adding, I have a 1476L tub?

To lower TA you can reduce PH to 7.0-7.2 with acid and then aerate to increase PH.

The method to do this is add acid turn on jets, check, repeat as necessary until your down to around 60ppm...is this correct? Is there a post somewhere that discribes this in procedure in a little more detail (ie timings)

Is the TA increaser on the pool calculator for baking soda as the borates mentioned above?

Thanks again for all the guidance, I don't think I would have ever attempted this without all the sound advice.

T

[chem geek]

For a pool, you can get the larger size Proteam Supreme Plus which is pH balanced so you don't need to add acid. Or if you were going to use 20 Mule Team Borax because it is less expensive and you were going to add acid, then of course you could do that instead. Up to you.

You only add the Borates once until you next change the water in the spa, but then obviously need to add it again since it isn't in the fill water. For a pool, it will slowly drop over time depending on the amount of splash-out or backwashing you do.

The TA on The Pool Calculator is for pure sodium bicarbonate which is Arm & Hammer Baking Soda or Alkalinity Up products.

[Nitro]

To lower TA you can reduce PH to 7.0-7.2 with acid and then aerate to increase PH.

The method to do this is add acid turn on jets, check, repeat as necessary until your down to around 60ppm...is this correct? Is there a post somewhere that discribes this in procedure in a little more detail (ie timings)

In a 350 gal tub 8 oz of Dry Acid will lower TA by 100ppm.

1) Calculate how much you need to lower your TA, and how much acid you need to add.

2) Add HALF (but not more than one cup or less than 1 oz) of the amount of acid you need to add.

3) Aerate for 30min, and check TA/pH.

4) If TA > goal and pH is > 7.8, goto step 2.

Example:

Your TA is 300, you want to lower it to 60ppm, in a 350 gal tub.

You need 2.4 cups dry acid.

Add one cup acid.

Aerate 30mins, check TA/pH.

TA=200 and pH=8.0

Add 6 oz.

Aerate 30mins, check TA/pH.

TA=125 and pH=8.0

Add 4 oz.

Aerate 30mins, check TA/pH.

TA=75 and pH=8.0

Add 1 oz

Aerate 30mins, check TA/pH.

TA=60 and pH=7.6

The main thing to remember is to add more acid in the beginning, and less at the end.