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AE340B
05-27-2007, 12:28 PM
I just received my first full featured test kit. It's a Taylor K-2006. Prior to this I was just using the small kits that measured free chlorine, Ph and alkalinity. This is my first time with a broader spectrum of numbers. Here they are, what do I do with this water, in what quantities and order, and in what amounts? It's a 44,000 gallon vinyl liner in ground pool on Long Island, NY. It's heated with a heat pump and water temp at this testing was 79 Degrees F. Thanks!
Ph - 7.0
6 drops of R-006 raised it to 7.5 - 7.6
Total Alkalinity - 50 PPM
Free Chlorine - 2.4 PPM

Combined Chlorine - amount didn't register, sample never turned pink ( I used the same sample as the free chlorine - was that correct, or do I refill the tube again with fresh pool water to retest for combined chlorine?)

CYA - 7.0
Calcium Hardness - 110 PPM
Ph Saturation - 8.15
Ph Saturation Index - -1.35
Anyone have any ideas on what to do here? Is any of this really bad? Why don't I have a Combined Chlorine reading? Lots of info here, but I don't know what to do with it. Thanks. :)
Doug

traceyb
05-27-2007, 03:02 PM
the alkalinity is raised w/ baking soda, this will also raise your ph and help w/ your chlorine. By the upper level of results, you would add 2-4 pounds of baking soda till your ph is ideal. then add your chlorine.

Hope this helps

AE340B
05-27-2007, 05:57 PM
So if I understand you correctly, I throw in 4 pounds of Arm and Hammer, and that will raise my alkalinity in my 44,000 gallon pool to where it needs to be. As a result of this, my Ph should rise along with it. Is this correct?

Also, any ideas why I showed no combined chlorine? Is this the way it's supposed to be, or do I have a problem? Did I conduct the teat properly? Lastly, this is the first time I tested for CYA. Are the numbers for that good, or do I have a problem? Thanks !
Doug

chem geek
05-27-2007, 06:12 PM
It is normal to not show any combined chlorine. If you did the test correctly, you started with your pool water sample (25 ml or 10 ml depending on the resolution you want), you added 2 scoops of powder (R-0870), the sample turned red/pink, you then added drops of titrant (R-0871) and counted them, then the sample turned colorless and the number of drops was multiplied by 0.2 if using the 25 ml sample or 0.5 if using the 10 ml sample to get Free Chlorine, then you added 5 drops of R-0003 and IF there is any Combined Chlorine the sample turns red/pink and you add more titrant (R-0871) until it turns colorless. It sounds like your Combined Chlorine (CC) was zero and that's normal. Combined Chlorine is a bad thing, not a good thing, so having it at or near zero is what you want (and currently have).

Don't worry about your saturation index since you have a vinyl pool so don't need as much Calcium Hardness (CH) unless you've got some exposed grout in tile touching the pool water.

Did you mean 70 ppm for your CYA reading? 7.0 doesn't make sense. The tube only measures from 30 (at the top) to 100 (near the bottom).

You need to raise your pH as well as your Total Alkalinity (TA) so I suggest using Sodium Carbonate which is in Washing Soda (not Baking Soda) or is sometimes called Soda Ash or is in pH Up from the pool store. You need to add 116 ounces (7.25 pounds) of it to your 44,000 gallon pool (that's a very large pool) to raise your pH to 7.5 and your TA will rise to about 70 ppm which should be fine. Add half of this amount and retest pH after a day, just in case your measurements are off. Then add more as needed.

What are you using as your source of chlorine? The low pH and TA and the higher CYA imply that you may have been using Trichlor pucks/tabs. You should stop using those and switch to a chlorine source that does not have CYA in it such as chlorinating liquid or bleach (or Cal-Hypo, but this will increase calcium hardness over time). At your 70 ppm CYA level (if that is your CYA reading -- not the 7.0), then you need to maintain between 5 and 10 ppm Free Chlorine (FC) as seen in this chart (http://www.poolforum.com/pf2/showthread.php?t=365) in order to prevent algae.

Richard

AE340B
05-27-2007, 07:05 PM
It is normal to not show any combined chlorine. If you did the test correctly, you started with your pool water sample (25 ml or 10 ml depending on the resolution you want), you added 2 scoops of powder (R-0870), the sample turned red/pink, you then added drops of titrant (R-0871) and counted them, then the sample turned colorless and the number of drops was multiplied by 0.2 if using the 25 ml sample or 0.5 if using the 10 ml sample to get Free Chlorine, then you added 5 drops of R-0003 and IF there is any Combined Chlorine the sample turns red/pink and you add more titrant (R-0871) until it turns colorless. It sounds like your Combined Chlorine (CC) was zero and that's normal. Combined Chlorine is a bad thing, not a good thing, so having it at or near zero is what you want (and currently have).

Don't worry about your saturation index since you have a vinyl pool so don't need as much Calcium Hardness (CH) unless you've got some exposed grout in tile touching the pool water.

Did you mean 70 ppm for your CYA reading? 7.0 doesn't make sense. The tube only measures from 30 (at the top) to 100 (near the bottom).

You need to raise your pH as well as your Total Alkalinity (TA) so I suggest using Sodium Carbonate which is in Washing Soda (not Baking Soda) or is sometimes called Soda Ash or is in pH Up from the pool store. You need to add 116 ounces (7.25 pounds) of it to your 44,000 gallon pool (that's a very large pool) to raise your pH to 7.5 and your TA will rise to about 70 ppm which should be fine. Add half of this amount and retest pH after a day, just in case your measurements are off. Then add more as needed.

What are you using as your source of chlorine? The low pH and TA and the higher CYA imply that you may have been using Trichlor pucks/tabs. You should stop using those and switch to a chlorine source that does not have CYA in it such as chlorinating liquid or bleach (or Cal-Hypo, but this will increase calcium hardness over time). At your 70 ppm CYA level (if that is your CYA reading -- not the 7.0), then you need to maintain between 5 and 10 ppm Free Chlorine (FC) as seen in this chart (http://www.poolforum.com/pf2/showthread.php?t=365) in order to prevent algae.

Richard

Thanks, Richard-
I did the combined chlorine test exactly as you described. I put the drops into the preciously used sample and it never turned the water pink again.

As I read your response I went back and rechecked my kit - I actually used the wrong scale on the tube for the CYA measurement. Using the proper scale, my CYA is actually 50. Is this a decent number or does that pose a problem? As for the question of what I'm using for chlorine, I am using the pucks. I'm gone from home frequently and my wife wants NOTHING to do with maintaining the pool. I need something that will auto-dispense while I'm gone. Will another form of chlorine work in my Hayward chlorine dispenser? Are there any other options other than the pucks that I can use to auto-chlorinate my pool? I can't swing the salt to chlorine setup now financially, but is that a better setup that I should work towards?

What brand name is "washing soda" or "soda ash" available as in the stores? Is this the same as Borax? Where can I buy it? I try to avoid "pool store" cures when I can as the tend to be SO overpriced. Is there a calculator available on line or here that shows how you came up with the amount I need? By the way, my pool IS actually 44,000 gallons - it's way too big! We sort of got caught up in the "...for a bit more we can go bigger..." routine. It's our first pool, if we ever move and do it again the new one will definitely be smaller! :)
Thanks for all your help and patience with this neophyte!
Doug

chem geek
05-28-2007, 01:35 AM
So no pink for the second part of the test means you have no Combined Chlorine (CC) and that's good.

Good catch on reading the wrong scale. Sorry I didn't think of that. 50 ppm CYA is fine and just means you should have from 3-6 ppm FC in your pool (I'd try and target closer to 6 ppm).

As for auto-dispensing chlorine slowly and automatically, that's tough since Trichlor is the most convenient for this purpose, other than a saltwater chlorine generator (SWG), but unforutnately Trichlor will increase CYA levels. Having used Trichlor in your Hayward chlorine dispenser means you cannot use any other source of chlorine (i.e. no hypochlorite source such as Cal-Hypo) in that dispenser -- ever. There are slow dissolving Cal-Hypo tablets and those are an option for you in some sort of floating dispenser, but they don't dissolve as cleanly as Trichlor. Cal-Hypo also adds to Calcium Hardness (CH), but that is not a problem for your pool since it's vinyl and your CH is already low so adding more, at least for a while, should be OK until you get to around 300-400 ppm or so. If you are gone only now and then, perhaps you can use chlorinating liquid or bleach while you are around (adding it directly to the pool slowly either over a return or into the skimmer with the pump running) and when you are away turn on the Hayward with Trichlor.

Perhaps someone else has a suggestion for what you can do more "automatically". You can, of course, continue to use Trichlor (especially when you are away), but should either drain/refill your water to keep the CYA level low or if the CYA goes up, then you'll need to increase your Free Chlorine (FC) level according to this chart (http://www.poolforum.com/pf2/showthread.php?t=365).

The store product that is equivalent to "pH Up" in pool stores and is simply sodium carbonate is "Arm & Hammer Super Washing Soda" as seen here (http://www.thelaundrybasket.com/Our_Products/Our_Products_Super_Washing_Soda/our_products_super_washing_sod.html).

Richard

adesalvo
05-28-2007, 03:35 AM
You need to raise your pH as well as your Total Alkalinity (TA) so I suggest using Sodium Carbonate which is in Washing Soda (not Baking Soda) or is sometimes called Soda Ash or is in pH Up from the pool store.

Why not use baking soda in this scenario? It seems that the sodium bicarb would raise both the TA and pH.

What am I missing?

CarlD
05-28-2007, 07:19 AM
Richard's given you good advice.

Your CYA at 50 is fine, but I consider that the high end of the ideal range for our area (I'm in North Central NJ). I would NOT use Tri-chlor pucks at this time unless you must.

VERY IMPORTANT!!!!! NEVER, NEVER, EVER PUT ANYTHING IN YOUR AUTOMATIC FEEDER BUT TRI-CHLOR PUCKS! ANYTHING ELSE IS AN EXTREME SAFETY HAZARD!!

If you continue to use pucks, as Chem_Geek said, your CYA will rise to levels that require MUCH higher chlorine levels. Tri-Chlor is also very, very acidic, which explains your pH of 7.0. With vinyl, 6.9 is the minimum. Below that the acid may begin to degrade the vinyl.

Baking Soda does not raise pH significantly but it does raise Total Alkalinity (TA).

All Chem_Geek was suggesting was that since you need to raise both pH and TA, you can use Arm&Hammer Washing Soda (in the Yellow box) rather than using both Baking Soda and Borax.

Why would you do this? Generally, pound for pound, at the supermarket Washing Soda is a little cheaper than Borax. But more importantly you only need to add one chem to get both effects.

99 times out a 100, I'll use Borax to raise pH, especially since I'm generally facing higher TA levels (140 or so--which is fine in vinyl pool with no heater). Borax won't increase TA levels, sort of. Washing Soda will. (as pH rises and falls, TA goes up and down with it. W/S raises the TA more than the pH rise does alone.)

So the other day my pH was 6.9 (VERY unusual for me) and my TA was 50. IDEAL conditions for using Washing Soda rather than Borax and Baking soda.

Oh, that base demand test (and the acid demand test) are virtually worthless, even in the 2006. You will figure out very quickly how much of each chem to add. With your pool (40,000+ gal), and your pH, I'd start with 2lb of Washing Soda, wait a couple of hours and check again. If you use Borax and Baking Soda, I'd start with 2 lbs of Borax (Half a box) but only one pound of Baking Soda. Lowering TA is a pain in the neck--all the way to your ankles--so it's far better to go slowly and approach your target gradually.