How Much Bleach Per Gallon?

[soakerman]

I am curious if there is a formula to use when adding bleach to a spa an a per gallon bassis to use the proper amount to maintain a free chlorine level of 4 ppm. and also to shock the spa at 10 ppm? I have a 325 gallon spa and want to use the bleach instead of the shock and Dichlor with stabilizer in it, or is the dichlor ok to use untill it is used up without raising the cya levels? I also have a mineral stick " spa frog" That after reading alot of post it appears it is a waste to continue useing this product?Thanks for your help.

[waterbear]

I am curious if there is a formula to use when adding bleach to a spa an a per gallon bassis to use the proper amount to maintain a free chlorine level of 4 ppm. and also to shock the spa at 10 ppm? I have a 325 gallon spa and want to use the bleach instead of the shock and Dichlor with stabilizer in it, or is the dichlor ok to use untill it is used up without raising the cya levels? I also have a mineral stick " spa frog" That after reading alot of post it appears it is a waste to continue useing this product?Thanks for your help.

1//4 cup of bleach should raise your spa in the neighborhood of 4 ppm and 1 cup to about 10 ppm (this would be either 5.25% regular bleach or 6% ultra bleach. It's not an exact measurement and it will get you in the ball park, but then again, it's a spa and not rocket science! If you want it more exact 1/2 tablespoon of regular bleach will raise 100 gallons 1 ppm and .45 tablespoon of the ultrra will do the same! So if you are using dichlor an easy way to switch is to use about 2 tablespoons (1 oz) of bleach for each teaspoon of dichlor you were using. It will be pretty close. Test your water with a good test kit before and after dosing and you will know exactly how much bleach will cause a certain ppm rise in your tub. For example, if you start at 2 ppm FC and add 2 oz of bleach and then have a reading of 4 ppm you know that 2 oz of bleach will raise your tub 2 ppm.

Hope this helps.

Hope this helps.

[Wrinkles]

Just for reference, I just added 3 oz of regular bleach to my 300 gal spa and it took it from 0ppm to just over 10ppm.

I didn't want to shock it but just bring it up a little but that's what I got.

[chem geek]

Something is not right about that. 3 fluid ounces (that's 6 tablespoons) of 6% bleach in 300 gallons should raise the FC by 4.8 ppm (about 5 ppm). You saw double that. That either means that the bleach was closer to 12% (unlikely, unless you use chlorinating liquid which indeed is around 12.5%) or the spa is closer to 150 gallons. It is also possible that the chlorine was not fully mixed in the water, though if you had the pump circulation on it should get mixed rather quickly.

I think I found at least a partial answer. Look at this link where it says that your Catalina CL Series 300 spa has a water capacity of 190 gallons, NOT 300 gallons. Of course, this link could be wrong. Next time you refill your spa, see if you can measure its capacity. If it's filled with a hose or through some inlet, time how long it takes to fill a large bucket and then time how long it takes to fill the spa.

[Wrinkles]

I'll take a look at that chem geek. I thought I had read in one of my manuals that it does hold 300 gal but I may be wrong. I know I have a 300 gal stock tank for my turtles and it looks like about the same size.

If it is only 190 gal, that sure would explain why it went up so high.

Just took a look at that link and that is not what I have. I have a Catalina CL 300 which is this one:

http://www.catalinaspas.com/designs/celebrity/

It does hold 300 gal.

[Wrinkles]

chem geek,

The bleach I am using is made by Clorox and it is unscented and says it is 'regular bleach'. I tried looking on the label and there is nowhere where it says what the chlorine % is.

As far as the 3 oz goes, it took 8 Tablespoons. I'm using one of those glass kitchen measuring cups sitting on the table. I dunno.

As far as the level goes, I tested about an hour after I had put the bleach in with the jets running. The next day, it tested at 3ppm

So, either my test strips are not accurate(I ordered the Taylor Kit) or maybe I have the wrong bleach.

[waterbear]

chem geek,

The bleach I am using is made by Clorox and it is unscented and says it is 'regular bleach'. I tried looking on the label and there is nowhere where it says what the chlorine % is.

that would be the correct bleach

As far as the 3 oz goes, it took 8 Tablespoons. I'm using one of those glass kitchen measuring cups sitting on the table. I dunno.

2 tablespoons per oz. 8 tablespoons would be 4 oz or 1/2 cup.

As far as the level goes, I tested about an hour after I had put the bleach in with the jets running. The next day, it tested at 3ppm

So, either my test strips are not accurate(I ordered the Taylor Kit) or maybe I have the wrong bleach.

You have the right bleach but you now know why many of us don't recommend test strips for water balancing!

hope this is helpful

[Wrinkles]

Well, I feel a little on the stupid side right now. I just went out and took a look at the bottle I have the bleach in which I marked every 2 oz on the side and instead of using 3oz, I went to the next line which was 6oz. No wonder it went up so high. I wish I could delete my posts

Anyway, now that I know what happened, does the chlorine level going back down to 3ppm the next day mean that my ozone generator is working?

[chem geek]

Don't worry about the mistake. If I got paid for every time I made a mistake, I'd be a very rich man indeed.

If you kept your spa covered and did not have the jets running, then yes your ozonator is probably working because normally the chlorine wouldn't drop quite that much that fast. If you use the spa, however, then the chlorine can drop very quickly as the combination of heat and aeration can outgas quite a lot of it and much will also get used up by sweat.

[104 Degrees]

Don't worry about the mistake. If I got paid for every time I made a mistake, I'd be a very rich man indeed.

If you kept your spa covered and did not have the jets running, then yes your ozonator is probably working because normally the chlorine wouldn't drop quite that much that fast. If you use the spa, however, then the chlorine can drop very quickly as the combination of heat and aeration can outgas quite a lot of it and much will also get used up by sweat.

Chem geek whats the "taylor kit"

Well, I feel a little on the stupid side right now. I just went out and took a look at the bottle I have the bleach in which I marked every 2 oz on the side and instead of using 3oz, I went to the next line which was 6oz. No wonder it went up so high. I wish I could delete my posts

Anyway, now that I know what happened, does the chlorine level going back down to 3ppm the next day mean that my ozone generator is working?

Ive done this no big deal

[chem geek]

The test kit referred to is the Taylor Technologies K-2006 kit you can see at this link direct from Taylor for $71.05. There are other test kits available from other manufacturers as well, but the important thing is to have a test kit that has a FAS-DPD drop-based chlorine test, plus tests for pH, Total Alkalinity (TA), Cyanuric Acid (CYA) and Calcium Hardness (CH). You can often find the Taylor kit at somewhat lower prices at certain retailers including on-line. For example, this link sells the same kit for $59.90 while this link sells the kit for $53.14 and this link has it for $49.00. I have not purchased from any of these retailers and have only purchased from Taylor directly.

If you have a bromine spa, then the Taylor K-2106 is the kit to get instead. It tests for total bromine (using a FAS-DPD drop-based test) instead of free and total chlorine and it does not have the CYA test since that is not needed. Taylor sells the kit for $66.75 and again, I'm sure you can find it online or at some stores for less.

[104 Degrees]

The test kit referred to is the Taylor Technologies K-2006 kit you can see at this link direct from Taylor for $71.05. There are other test kits available from other manufacturers as well, but the important thing is to have a test kit that has a FAS-DPD drop-based chlorine test, plus tests for pH, Total Alkalinity (TA), Cyanuric Acid (CYA) and Calcium Hardness (CH). You can often find the Taylor kit at somewhat lower prices at certain retailers including on-line. For example, this link sells the same kit for $59.90 while this link sells the kit for $53.14 and this link has it for $49.00. I have not purchased from any of these retailers and have only purchased from Taylor directly.

If you have a bromine spa, then the Taylor K-2106 is the kit to get instead. It tests for total bromine (using a FAS-DPD drop-based test) instead of free and total chlorine and it does not have the CYA test since that is not needed. Taylor sells the kit for $66.75 and again, I'm sure you can find it online or at some stores for less.

Thanks Chem geek. Can you use a pool test kit till the taylor comes in?

[chem geek]

The same test kit is used for both pools and spas. The two kits I referred to only differ in their testing of chlorine vs. bromine. What are you testing for (chlorine or bromine) and what kind of "pool test kit" do you currently have or are referring to?

[104 Degrees]

The same test kit is used for both pools and spas. The two kits I referred to only differ in their testing of chlorine vs. bromine. What are you testing for (chlorine or bromine) and what kind of "pool test kit" do you currently have or are referring to?

Chlorine(dichlor) The test kit is HTH - OTO test kit for Chlorine,bromine,PH.

Thank you 104 Degrees

[chem geek]

Yes, you can certainly use your existing test kit for chlorine level (and for pH). It is just harder to know the true free vs. total chlorine level with an OTO kit, but to get a rough idea of chlorine level it's fine. It also doesn't bleach out at very high chlorine levels (say, for shocking) though it won't tell you exactly how much chlorine you have (i.e. it'll just be > 5 ppm).

The FAS-DPD drop-based chlorine test has a precision of 0.2 ppm or 0.5 ppm depending on the sample size you choose to use (so you use the smaller sample size that increments at 0.5 ppm for each drop when you know you have lots of chlorine, say after shocking).

[104 Degrees]

Yes, you can certainly use your existing test kit for chlorine level (and for pH). It is just harder to know the true free vs. total chlorine level with an OTO kit, but to get a rough idea of chlorine level it's fine. It also doesn't bleach out at very high chlorine levels (say, for shocking) though it won't tell you exactly how much chlorine you have (i.e. it'll just be > 5 ppm).

The FAS-DPD drop-based chlorine test has a precision of 0.2 ppm or 0.5 ppm depending on the sample size you choose to use (so you use the smaller sample size that increments at 0.5 ppm for each drop when you know you have lots of chlorine, say after shocking).

Thank You Chem Geek

[Wrinkles]

What is the difference between Calcium hardness and Total Hardness or is it the same thing?

Just wondered because my old test kit had a test for Total Hardness and not the CH.

[chem geek]

The Total Hardness tests for both Magnesium and Calcium. Typically, Calcium Hardness is around 70% of Total Hardness (when both are measured as ppm calcium carbonate which is the typical way these are measured), but this depends on the source of the water.

Only the calcium in the water affects the calcium carbonate water balance that is what you want to achieve in plaster/gunite pools. The magnesium has no effect and is far more soluble. So it is the Calcium Hardness that should be used for pool water balance, not Total Hardness.

[Wrinkles]

Thanks for that info on the CH & TH.

[cchaynes]

I know this thread is old but its great!

Quick question, do you recommend using bleach over dichlor in general?

We have a Hotspring with the Freshwater slat system.  It has been a bit light on production and the dichlor spiked our CYA so we needed to start over today.

Thanks
Craig

[WickedTub]

Sorry to dig up an old post but I'm new and curious about using bleach instead of dichlor chlorine granuals... how much bleach would I need for my old 1998 390 gallon (basically 400) sundan altamar to maintain 2 to 4ppm FC and how much should I toss in per bather after we use the tub.. I also use a frog mineral stick..(that's another question my filter sits horizontal in the skimmer and the frog directions say to place inside the filter but not with a pump that's 2.5hp which mine is so should i just place it in the skimmer area or is it fine inside the filter)

[RDspaguy]

1-2 fluid oz.

Just toss it in by the filter.

 

 

[waterbear]

You don't want to use bleach if there is no CYA (stabilizer) in the water. Read the pinned post about Dichlor/Bleach in the hot tub water chemistry section of the forum