Doing dichlor-then-bleach method, something's not working so far

[davesurfer]

So I'm finding I have to add a lot of bleach, more than double the PoolMath calculator recommends. For example, this morning I had 2.5 FC, I put 7.5 FC as a goal and added 130 ml. (assuming 2500 L). I tested 15 minutes later and only got 4.5 FC! Right now my CYA is about 35 or so. TC at 1. Is it because this bleach which says "concentrated" is just regular 6% stuff and not the 8.25%? What am I doing wrong?

Thanks!

 

[nlindelldc]

I see several possibilities: The easiest to check is to look at the concentration of the bleach on the bottle. It will always (or should) say (8.25%, etc.)

Second, check the date code. Do a search on that if you need to

Third, the volume of the pool you are putting in Pool Math is wrong. There is a calculator for that at the bottom of PoolMath.

Check those 3 things and we'll go from there

I just saw you have a spa, but the above 3 (mostly first 2) still apply

 

[tim5055]

Now, you are north of the border, so the labeling may not be exact, but her in the stated if it says "concentrated" it is usually 8.25%. But, as a rule I don't buy it unless it actually has the % printed on the package. Checking the date codes is a really good idea as sometimes you end up with a really old bottle. I've been watching a few cases of 10% at my local Lowes that has just been sitting in outside garden with early 2014 codes.....

 

[davesurfer]

So frustrating, there is NOTHING regarding percentage on the bottle, doesn't list ingredients and says to go to The Clorox Company | Products | Ingredients Inside for the ingredients where this bottle is not listed. It's a Chlorox "Original" and in small print it says "Concentrated Bleach" I would've attached an image but I'm getting a "exceeds quota" error, I've tried to size down the image and quality to like only 33kb but it's still saying exceeding by 25k!

Regarding date code, no idea. It says E615301 M02 2 10 and on the bottom it says 76 MA7166.

I can't figure out the volume of the hot tub. I thought I did one time when I filled it and it seemed to be 1500 L. It's a Sundance Calypso which has NO information on the volume at all in the manual. I'm actually putting in 2500 L in the calculator because that's giving me a better estimation for bleach, even though it seems to be only half and I don't think I have a 5000 L tub.

I added another 130 ml and now I have 9 FC in the tub ;p

 

[pooldv]

My first question is have you been sitting in the tub? If you have been it can take some extra bleach to oxidize everything. Are you testing after the pump runs a bit? And running the pump after you add? There might be some stuff in the plumbing that needs a clean out.

 

[davesurfer]

My first question is have you been sitting in the tub? If you have been it can take some extra bleach to oxidize everything. Are you testing after the pump runs a bit? And running the pump after you add? There might be some stuff in the plumbing that needs a clean out.

We haven't used it for a few days. I run the pump when I'm adding the bleach, so it runs for about 15 minutes and then I test it. I already did a plumbing clean and drain several weeks ago too.

Here's a pic of the bleach bottle: Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

 

[BuckeyeChris]

I would guess that date code means it was manufactured on the 301st day of 2015. Also, don't put any commas in your pool size in poolmath.

 

[davesurfer]

So tonight after we were in the tub for about 30 min, I tested it at only 0.5 FC and 1 CC. So putting this into the pool calculator with a 2500 L size (probably not that big, only 1500 L), it recommended 188 ml to raise the FC to 7, so I added that, after running the pump for about 15-20 minutes I checked the levels at the FC was only 5, not 7. And this is even with the higher 2500 L I put into the calculator, not 1500 L. Also, just bought new bleach from Costco, same brand same stuff, but probably gets a much higher turn-over so fresher. Again says "concentrated" in small print.

I still don't know what's going on. And would the hot tub be really that dirty that it uses up 2 ppm of FC in 15 minutes? At that rate there would be nothing in an hour! So confused..

 

[pooldv]

Sometime around two years ago I calculated that we would use about a 1/4 cup, 60ml, of 8.25% bleach per person hour in our tub, 340 gal, 1300 l. That is 2ppm. I don't know how long it actually takes to to drop the 2ppm. It has been a while since I paid that close of attention and retested.

 

[ewkearns]

I can find "Clorox® Bleach/Eau de Javel Clorox® (Canada)", but I cannot find a "concentrated bleach" in their MSDS. (There is a Clorox® Regular-Bleach1/Eau eu de javel Clorox® ordinaire (Canada)) .

The former product seems to be 5% and the latter is 5%-10%.....

 

[davesurfer]

So I checked it in the early afternoon, it was about 2 FC. So I added 200 ml of bleach and tested it at 6.5 FC. On the PoolMath calculator if I have 2 and have a goal of 6.5 it tells me I only have to add 78 ml.

So I'm finding I'm having to add over twice what the calculator says to add. And I'm pretty sure my Calypso Sundance 6-seater tub is 1500 L. With the amount I'm putting in, it's like the concentration is 3.4%.

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I can find "Clorox® Bleach/Eau de Javel Clorox® (Canada)", but I cannot find a "concentrated bleach" in their MSDS. (There is a Clorox® Regular-Bleach1/Eau eu de javel Clorox® ordinaire (Canada)) .

The former product seems to be 5% and the latter is 5%-10%.....

5-10%? That's a pretty big range. So even if I put 5% in the calculator it only recommends 133 ml, I'm putting in 200 ml to go from 2 FC to 6.5 in my 1500 L tub.

 

[WASP]

Is the bleach old stock?

 

[spanoob9]

When buying bleach I always look for one that says 8.25% sodium hypochlorate, and non scented. It will usually also say 'adds x amount free chlorine'. If it doesn't list ingredients its usually non intended for use as chlorine as it may contain fabric softener or additives or splashless additives.

Also it does have a limited shelf life, if its old and your not getting the FC it may be weakened and (I think ur OK just doubling up unti you finish the bottle)

 

[davesurfer]

Is the bleach old stock?

The only bleach Costco sells, so I'm sure they go through a lot of turn over and it shouldn't be old. Chlorox.

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When buying bleach I always look for one that says 8.25% sodium hypochlorate, and non scented. It will usually also say 'adds x amount free chlorine'. If it doesn't list ingredients its usually non intended for use as chlorine as it may contain fabric softener or additives or splashless additives.

Also it does have a limited shelf life, if its old and your not getting the FC it may be weakened and (I think ur OK just doubling up unti you finish the bottle)

Yeah it's not splashless, I already made that mistake and it makes a lot of bubbles. But it's the stuff Costco sells, Chlorox. I wonder where I can buy a brand that actually lists the percentage??