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Demegrad9

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May 27, 2017
360
Coventry, CT
Ok, first post (after the intro post). I've been testing our pool with the K-2005 test kit. And then my girlfriend got her friend who works in the pool industry to test the water with more lab scale equipment. Overall the readings have actually been really close so I guess that good. I see a couple things as real problems because this pool was maintained for a couple decades as a trichlor pool but overall the pool looks nice and clean and I'm happy I'm moving in a different direction. Let's start with the test results:

My recent tests with the Taylor K-2005:
FC=3;TC=3;pH=7.4;Total Alk=90;CH=270;CYA=~100

More accurate lab test
FC=2.5;TC=3.6;pH=7.5;Adj Alk=65;CH=253;CYA=118;Metal=0.3;TDS=800;

I do believe the more accurate test more or less BUT the TC is strange to me. I would think my K-2005 test should show SOMETHING if CC was actually 1.1ppm plus I went into the pool for a while and opened my eyes and smelled the water and it's not irritating and the smell is extremely faint chlorine smell, practically none at all. From reading I thought even very low CC, ~0.2ppm, would cause my skin to smell of chlorine, am I wrong. Also I just learned about adjusted alkalinity so it looks like those readings are pretty darn close.

Anyway, my current plan is to switch over to Sodium Hypo, I found a place willing to sell me 5 gallon carboys for $19.55, is this a good price??? And I'm setting up a peristaltic pump on a timer and syched with the water filter pump (sand filter) timer so once that up and running I feel like I'm pretty fine tuning on chlorine. Overall I'm hoping to lower CYA and metal over time with regular backwash and refill because I'm on a well and don't want to drain and fill the pool. The metal is most likely copper because the 'pro' who used to take care of this pool had the previous owner using substantial weekly copper based algecide additions (probably because of high CYA levels). Anyway, with the switch I'm doing I hope to not need the algecide; but I'm still using a little for now until CYA levels drop dilution.

Well I think that's it. Any comments are very much welcome. I guess my big question at the moment is should I shock again to reduce combined chlorine. The 'pro' just shocked it 2 weeks ago and we had very high, >10ppm, FC for a week straight. I would think that should do it, plus there is no indication of high combined chlorine, so I don't know...
 
Well, a few things to help you:
- Remember, FC + CC = TC. You can't test or separate FC from CC with the 2005 OTO viewer. Your need an FAS-DPD (which comes with the 2006 version) to accurately test those. You can get the FAS-DPD HERE. That will essentially convert your 2005 to a 2006.
- The #1 thing you need to confirm right now is CYA. If it's over 90, you're going to need to exchange "some" water to lower it. But it's difficult to test CYA over 100, so follow the diluted method as seen on the TFP Pool School - CYA page, starting at step 8.
- As for the bleach, I don't think that's a great price myself. I get Wal-Mart's Great Value 8.25% bleach for just under $3 a gallon. Maybe someone else in your area will chime-in with some thoughts about that.

But definitely confirm the CYA. That's the most important part of everything right now. Also note that we don't shock pools as what we all grew-up hearing. We "SLAM" them as noted on the SLAM page (link below). Based on the accurate CYA, we increase FC to a specific level that matches on the Chlorine/CYA Chart which is another reason why you need that FAS-DPD kit ASAP. Hope that helps.

Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.
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Ellington CT, here. Assuming that it's 12.5% chlorine that you are getting for $3.91 per gallon, you can do better. Ocean State Job Lots sells 1 gallon jugs of 12.5% for $2.99. I go to their Enfield store where there is high turn over and therefore it is always fresh. The Manchester store may be closer to you. As for your plan to reduce your cya over time, I did the exact thing when I first started with the TFP method. I slowly brought it down by over the fist season by small draw downs prior to rains and refills after back washing. I even used my pool water to water my grass. During this you will need to keep your FC at 7.5% of cya. At the start my cya was around 140, so I just keep my target FC 11 ppm (140 * 0.75= 10.5) and reduced FC target as I brought cya down to around 60 ppm by the end of the season. If you are going to do this its important to know what your cya is. SSsince your appears to be over 100 ppm, I suggest that you use the diluted procedure to test cya your self. Also you need to keep a close eye on your FC during this time, since falling l below the appropriate level for your cya runs the risk getting algae growth which at high cya levels will require lots of chlorine to combat.
 
Thanks for the quick response!

On the price of Sodium Hypo, my source is selling 12.5%, I forgot to mention that, so it looks like that would still be a good price and prevent me from having to go to walmart and lug 1 gallon jugs around.

On the note about the CC with K-2005 kit. Side note, I'm definitely getting the better kit. BUT the K-2005 does have the R-0003 DPD reagent #3. So as I go through the procedure of 5 drops of R-0001 and 5 drops of R-0002 I get the free chlorine, then I add 5 drops of R-0003 and, at least the kit claims, I color match to get total chlorine. Then of course TC-FC=CC. But when I do this test the R-0003 does absolutely nothing to the color, which is good right? I would think this test would show something if the TC was actually as high as lab results say. I guess I'm asking, is the experience with the K-2005 total chlorine test is known to be completely worthless?

I'll have to looking into the SLAM method a bit more. Probably once I get my new chlorinator setup done.

On the CYA issue, I'm really trying to not to drain and fill, can't I just use the Chlorine/CYA chart to determine what FC level I should keep it at until the CYA content is down through regular dilution?
 
But when I do this test the R-0003 does absolutely nothing to the color, which is good right?
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You would think so, but those viewers are simply not as reliable as the FAS-DPD "powder & drops" testing. You'll see once you receive it. I only test my FC & CC now with the FAS-DPD.

Feel free to review all the vital links you see below in my signature, and bookmark them as well for future reference. Don't forget to update your signature at some point as well. It's the first thing we look for in any post. :wink:

On the CYA issue, I'm really trying to not to drain and fill, can't I just use the Chlorine/CYA chart to determine what FC level I should keep it at until the CYA content is down through regular dilution?
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Yes, but again, over 100 it gets VERY tricky. First there's the accuracy of testing CYA via dilution. So the variance might increase a bit. Also, maintaining that elevated FC level to keep-up with the high CYA means your pH will always ready high. So again, a little tricky and something to keep in mind. As laprjns noted above, it can be done within reason, but very carefully.
 
Hi laprjns, wow you're really close actually.

Thanks for the tip on Ocean State. I've been in there but saw nothing but chlorine tabs so I'll have to ask someone who works there because I probably just missed it.

Okay, so my plan was to continue to use the copper based algecide until CYA comes down but it sounds like as long as I keep FC up around 7.5% I can cut that out right now, is that correct? I do believe CYA 118ppm number, I've tried testing with the K-2005 kit several times, not with dilution yet which I guess would get me a more accurate number, but I was pretty convinced myself that it was around 100ppm, then we had a lab test done and when it came back at 118ppm I'm feeling pretty confident about that one.
 
Okay, thanks guys. I'm feeling good about this. Once I get the FAS-DPD test I'll just keep a close eye on it and I'm going to try to be pretty aggressive with backwashing/refilling this year to hopefully balance pH, I have really nice soft 7.0 well water, and get CYA down.
 
Demegrad9 said:
Hi laprjns, wow you're really close actually.

Thanks for the tip on Ocean State. I've been in there but saw nothing but chlorine tabs so I'll have to ask someone who works there because I probably just missed it.

Okay, so my plan was to continue to use the copper based algecide until CYA comes down but it sounds like as long as I keep FC up around 7.5% I can cut that out right now, is that correct? I do believe CYA 118ppm number, I've tried testing with the K-2005 kit several times, not with dilution yet which I guess would get me a more accurate number, but I was pretty convinced myself that it was around 100ppm, then we had a lab test done and when it came back at 118ppm I'm feeling pretty confident about that one.
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I go to Ocean State for my Chlorine too. You need to look for the liquid pool shock (A.K.A. 12.5% liquid chlorine) Its usually stacked up in boxes in the open area just outside where they have the pool supplies.
 
Hi bigevilgrape, thanks for the tip. I did head over to the Manchester Ocean State and the stack of boxes of 'Shock' was so huge I didn't even realize what it was at first. I ended up buying 4 cases for the moment.

Just an update, I started adding liquid chlorine while using dilution and my K-2005 to measure FC. Overall, going from 3ppm to ~15ppm FC raised pH so I use a little dry acid to get it to 7.6. Finally yesterday I got some FAS-DPD reagents and I've tried that out and it turns out that using that I'm measuring with the 10mL sample I get 26.5ppm FC. I thought that must be wrong, more likely I'm doing something wrong, so I tried the 25mL sample and got 25.8ppm FC. So all week I thought I had ~15ppm FC with the DPD FC measurement, so I guess that just more proof you really need a FAS-DPD test when measure high FC, period.

Anyway, last night free chlorine loss was basically zero (I only did 10mL sample last night) so I think the best I can say is that the free chlorine loss was probably <1.0ppm overnight. This is good right?

Also pH is nice and steady at 7.6 which I plan to leave that as is for now as I expect it to fall as I let FC go down towards 12ppm FC. A note on CYA; since it was measured at 118ppm I've done 2 backwashes, each lowering the water line by 2 inches, then refilling. With 905 sqft surface area I calculate 2 inches is a bit over 1,000 gallons and should get me down to 108ppm CYA so far, looking to be ~40ppm by the end of the season.

Okay, so here's where my general thinking is. My low overnight FC loss means I should be okay to move ahead and bring FC level down to 12ppm FC based on the 108ppm CYA level, then maintain FC per the CYA/Chlorine chart. I bought some borax to do pH adjustment expecting pH to fall with my heavy backwashing and falling FC level. And from my calculations it looks like I'll probably have to do alkalinity adjustment about once a month. My big question, does it sounds like I'm on the right track or am I totally missing something?
 
OSJL is the best price I've found here in CT also. $2.99 for 128oz of 12.5%.

My PB is out of Coventry. Sabrina. Sounds like youre on the right track from my relatively beginner's vantage point. My understanding is that small adjustments in TA are not necessary as long as pH is relatively stable. My pH is 7.5 and my TA is 60 and neither have budged in the three weeks since raising them slightly with baking soda. If your pH is 7.6 and TA is 90 those are both inside the preferred ranges. Sounds to me like your only problem is the high CYA level which can only be changed by replacing water.
 

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hi jbb2388, I believe Sabrina originally built my pool as well. They've been around a long time.

On the high CYA issue, I've been backwashing or wasting a good bit and keeping track. Basically the math comes down to draining the pool ~2 inches is about 1100 gallons of water, so I just have an excel sheet where I record from my last known CYA reading and how much each dilution is reducing CYA. Based on that I think the CYA is now ~100ppm BUT I tried my K-2005 CYA black dot method and I know that is not the greatest test but it actually seem to be indicating closer to 90ppmCYA and maybe even a hair under that. We've gotten some rain, but closer to 2-3 inches recently, nothing that I would think could actually drop CYA substantially.

Overall, I've actually stopped stressing so much about it. Our FC has been falling slowly, ~0.8-1ppm per day, and we're currently at FC=17ppm measured by FAS-DPD 10mL sample measured this morning. And we've been finally getting some sun so the pool is actually getting some usage now. I'm basically just waiting for FC to fall to ~10ppm then I'll kick on the Rola-chem to dispense ~0.25gallons of 12.5% "Super Shock" each day to compensate for daily FC loss.

Actually the pool math calculator says I'll need 33 oz of 12.5%trade NaHypo, does anyone know if that is in fluid ounces? I did some searching but didn't find anything to clearly answer that question. I know the jugs of Super Shock I have are full gallons so I was just dividing the 33oz by 128 fl oz/gallon to get ~0.25 gallons/day in order to gain 1ppm FC. We're still in the process of actually determining the pool volume but we know it's around 32,000 gallons plus or minus 2,000 gallons or so.
 
Also just to note, one issue that was giving me stress about CYA level was that I thought having to have such a high FC level would make it uncomfortable for swimming. BUT even at 17ppm FC, I was in the pool for hours this weekend, I didn't notice any problems with chlorine smell or skin/eye irritation.

Back in days when I managed a seasonally pool, we never used any Stabilizer and just tried to keep FC levels between 2-5ppm. That experience was making me think that having much higher FC levels while required for sanitation would not be good for human comfort. But I can confirm that doesn't seem to be the case, just sticking to the FC/CYA chart seems to be great for both. As such my mind is much more at ease if all I have to do is monitor FC and keep it in the right range.
 
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