Trouble getting CC to zero.

[huskerfan]

I have an AG vinyl liner, de filter, northstar .5hp Hayward pump, 18x34:

cc- .6 or so
tc- 17
ph- 7.3
alk- 160
cal- 220
cya- 35-40
temp- 68

I've been patiently trying to get my cc to zero, or at least under .5. Last season it stayed around .4, didn't try to shock it out as was told .4 is ok. At the end of the season right before closing I used a different brand of bleach; the store looked up and told me it was 6percent, but after struggling to keep my chlorine regular and cc moving up to .6 I called the co. directly and found it was only 3percent. Long story short - had just a very few brownish slimy spots about dime size that I brushed and got rid of right away - switched to a 6 percent bleach, and due to the lateness of the season and other reasons had to close with a .5-.6 cc. My water was always crystal clear.

I opened to a clear pool on the 23rd of this month, with just a few spots of brownish dust on the pool floor in places. Ph was a tick low so regulated it with 20mule team borax and added 1 qt poly 60. We have iron in our water - so treated it firstly too with pool magnet for the fill water I had to add and let it filter for 3 days before adding chlorine (after I got a zero reading on iron from pool store). At this time my cc was up to 1.25, so I raised my chlorine up to shock level slowly, to 15. I did this for 5 days - a few times it got down to 12 or 13 on me checking it 3x's a day - raised it right away to 15 again. My cc came down to around .6 and it still hangs there. I've brushed once - but nothing to really brush, have run my pool rover plus every day, whether there's anything to pick up or not. Last night I decided to try to jump it up to 19 to overshock in hopes that that would break my cc, but still tests approx. .6. Right now my tc is down to 17. This morning my pool had just a very slight tinge of yellow to it, very, very slight. It is going away. I'm afraid if I would hold my chlorine level that high my iron will fall out. Should I take it back to 15 and check it more often and try to keep it there for a few more days and see if it will break below .5?? It takes too many drops of reagant to test using the 25ml line of pool water to get an exact cc total - so been guessing using the 10ml line. How long can you hold your pool up to shock level without hurting anything?? I'm on my 6th day of shocking now. I'd like to get this nipped in the butt so I can proceed to put my solar cover on and start running my solar panels so we can swim soon. Todays temp is supposed to reach 92, then back to the 70's the rest of the week. Would appreciate anyone's advice on how to get rid of my cc please. Many thanks!

[chem geek]

Is your pool exposed to sunlight? Does it have a cover? If you keep the pool uncovered during the day and exposed to sunlight then that should help get rid of the CCs. You've got enough chlorine to achieve breakpoint, but your CCs are probably not simple chloramines. They might be chlorine combined with more complex organic compounds that are harder to get rid of, but usually sunlight works well for those.

You'll know if your pool is exposed to enough sunlight if your FC level drops significantly during the day (up to half).

Richard

[huskerfan]

I have not put my solar cover on at all this year, as you shouldn't have them on when the pool is at shock level. Normally, without shocking, the cover is off daily for a minimum of 3 hours; then back on before nighttime.

In the last 3 hours my tc dropped from 17 to 13.5. I just added enough bleach to get it back to 17 again, as it's almost 90 today, super windy and super hot, so it won't be long and it'll be going down again. The good news is I've went from .6cc down to .5cc or less as I have no way of checking closer unless I fill my test tube to the 25ml line and check it that way - but I don't want to waste that many drops of my 0871 as I haven't been able to order a refill kit yet as the cart and checkout are not working on poolsolutions currently for me.

When I raised my tc to 19 last night - it was just border line of dropping my iron out of solution and it turned my water just a real faint yellow color. My pool's crystal clear now, so I think I'll stay around that 17 range for another day or so and see what happens. Does that sound reasonable to you? I love my de filter, it really helps me out with my iron issue too.

The last few days have been more overcast outside, but today's really sunny, so maybe that's the key to dropping my cc down. Thanks for pointing that out. I'd love to get it to 0, but if not possible for any reason, at least we can still swim with it at .4 or lower.

Do you have any other suggestions? Today is the day for my weekly poly 60 treatment - would you go ahead and add it, or wait until I get through with my cc issue?

A year ago I would have been stressed out over this - but I've learned a great deal from the forum and it's moderators and members. I actually feel kinda "professional" using my kit from Ben, lol! I love the BBB method, although I wish I didn't have to deal with iron everytime I fill, but at least I know how to manage it. Haven't dealt with cc much yet, so just wanted someone else's opinion on dealing with it. Thanks again.

[chem geek]

Donya,

I wouldn't worry so much about your CC level. I do think that with exposure to sunlight that it will reduce over time. As for the PolyQuat 60 addition, I would not add that when you have high chlorine since the chlorine breaks down the PolyQuat 60. The good news is that the broken polymer is still effective against algae (according to the manufacturer that I contacted) but there's not much sense in consuming so much chlorine at this point. If I were you, I would stop keeping the chlorine so high and just let it drop with sunlight. Just keep it above 5 ppm FC to ensure you have enough to finish off the CCs.

Are you adding PolyQuat 60 weekly just as an insurance policy to prevent algae in case your chlorine level gets too low? You shouldn't need to use a weekly algaecide unless chlorine levels drop too far (relative to CYA level). Also, if you have been regularly using Borates to raise your pH, you might consider raising their level to 30-50 ppm since that will also inhibit algae and you won't have to keep adding PolyQuat 60 which isn't cheap. See this thread (http://www.poolforum.com/pf2/showthread.php?t=4712) for more info about the Borates.

The CCs aren't a problem unless you notice a strong smell that prevents you from enjoying your pool. Keep us posted with what happens as sunlight starts to hit the pool.

Richard

[huskerfan]

When I opened this year is the first time I've ever had to use 20 mule team borax to raise my ph. Normally I never have to adjust my ph- -- maybe a cup of muratic acid to bring it down a tad once a month or so. My ph stays pretty balanced. I've been thinking about a SWG, but other than the additional setup expense, I hate to use muratic acid. I had some breathing/lung problems the way it is in the past and don't like to handle it any more than I need to. I went to our pool store's pool school the other night and they are pushing Bio Guard's mineral springs. They have a supplement you add that's supposed to take care of the ph issue, but don't know... (I only went because they give great door prizes, lol. I do buy a couple things from them - and need them to test my iron for me. They are fine with me using my methods, and I don't say anything in front of their other customers about it. They need to make a living too, just not off me :))

I use the poly 60 as a preventative measure. I get it online for $11 a qt. Probably wouldn't need it - but I use it anyway as long as I can get it cheaper. Last year I only paid $7 a quart. My water is always crystal clear and awesome to swim in, so will keep up my regular routine with it after my chlorine drops to normal again. I know there isn't a "perfect" pool, just wish my cc was 0. At least I finally broke that .6 level after 6 days, so am pleased with that. Thanks again for your time in replying and the advice, appreciate it! My landscaping is done so this summer will be pure enjoyment!

[chem geek]

Your TA is a little on the high side which can lead to a tendency of your pH to rise, though you seem to find it pretty stable. The next time you find your pH too low on opening, if your TA is high then instead of adding Borax, do aeration instead. That will cause the pH to rise with no change in TA. Though Borax doesn't add any carbonates, it will have the TA rise when it makes the pH rise (because they go together). It is only aeration that actually removes carbonates from the pool via carbon dioxide outgassing.

I wouldn't worry too much about the rising pH in SWG pools since keeping the TA low and using Borates does seem to help a lot. Yes, you probably will need to add acid more frequently than you do now, but it won't be as often as with most SWG pools where people don't know about the low TA and use of Borates. Check out the various threads on rising pH in SWG pools to see people's experiences and how much acid they need to add. It might be tolerable for you.

Anyway, it sounds like you've got a pretty nice and easy situation currently, except for dealing with iron in your fill water. You might consider using a water softener filter for the water -- you might even have one already for your house. Also, if you use a pool cover (such as the solar cover you mention), then that will significantly cut down your loss of chlorine during the day, will keep your pool warm at night and I'll bet that it's use is why you don't see much of a pH rise even with the higher TA.

As for BioGuard Mineral Springs, the "Beginnings" added at startup is just salt (sodium chloride), Boron salt (i.e. borates), and acid (inorganic and organic). The "Renewal" is just the same thing but with less salt and more Boron salt (borates) and inorganic acid and a little aluminum salt. In California, the Beginnings is just salt with a small amount of Cyanuric Acid (CYA) while in Renewal there is no Boron salt (borates) in the product and instead there is sodium bisulfate (acid). This dry acid adds sulfates to your water and high levels can cause problems, particularly with plaster (but we don't know exactly how high so generally just try avoiding adding too many sulfates) and I don't know if there are any issues with sulfates and vinyl pools (probably not). We do know that high levels of chloride and sulfates together are corrosive to stainless steel (especially with high chlorine levels).

The only thing in the product that helps with the rise in pH is the Boron Salt (borates). The products still add acid (at least partly to neutralize the borate that is alkaline) that is probably sodium bisulfate even outside of California (what is called "inorganic acid"). California identifies boric acid as a hazardous waste so that's probably why it's not put into the BioGuard products sold in California (it probably requires special labeling and/or handling requirements). If BioGuard were really on the ball, they would recommend a low TA setting with their system. I can't find their MS-10 or MS-20 product manual so don't know what TA they recommend.

You can check the price of the BioGuard Mineral Springs and compare it to the equivalent of adding Borax and dry acid (and salt) that you could purchase separately.

Richard

[duraleigh]

Huskerfan,

I'm a little confused by your CC's? How are you measuring .4 and .6 values? I am not aware of a test that precise.

[chem geek]

Dave,

The FAS-DPD chlorine test can measure Free Chlorine and Combined Chlorine each to 0.2 ppm since using a 25 ml sample size has one drop of titrant measure 0.2 ppm (the 10 ml sample size has one drop measure 0.5 ppm). You add 2 dippers of R-0870 powder which makes the sample turn pink if free chlorine is present, then add R-0871 dropwise until the sample turns colorless. The count of drops is Free Chlorine. Now you add 5 drops of R-0003 and the sample will turn pink if combined chlorine is present, then add R-0871 dropwise until the sample turns colorless. The count of drops (after adding the R-0003) is Combined Chlorine.

Richard

[duraleigh]

Thanks, Richard,

I had fogotten about doing that test with 25ml. Makes perfect sense to me now. (Tho, I'd have to say, that precision seems like a little bit of overkill)

Nevertheless, I understand now.

[huskerfan]

It's definitely overkill if your pool is at shock level! When it's not it doesn't take that much longer or that much more reagent. I was told .4 cc is acceptable, .5 or higher - shock, thus I measured with the 25ml level. LOL - I guessed .6 on my cc now, it was just barely pink after adding one drop of 0871. It actually could have been .7 or up. Sometimes you just gotta guess :).

Richard, I was told to only use one dipper of the DPD powder regardless if you were testing using the 25ml line or the 10ml line. Quite possibly I was told wrong, but it was from a very reliable source. You're absolutely right on the aeriation, but for now we're starting our planting season and didn't have the time to hook up the fountain, and too cold for these bones to jump in! The borax was handy and quick. My TA is a little high, but I read it's ok as long as it stays under 180. It'll drop as we start to swim too --- that's those times when I need a little muratic acid as my daughter is 10 and we have her friends over a lot - so it gets a lot of aeriation!

Will check the chlorine and cc levels once more before going to bed - will let it come down and get my solar blanket on tomorrow. When you fill with iron filled well water you don't want evaporation either.

Matt 4x4 talked about a brown dust algae where he had to overshock to get rid of it... wonder if that's what mine is. I don't think I want to shock over, let alone up to 19 again, as I don't want my iron to fall out.

After my chlorine drops to my normal rate I'll recheck my cc using the 25ml line and repost the actual number. I think I'm just gonna have to live with some cc in our pool. Thanks again!

[chem geek]

The Taylor instructions say to use two scoops and somewhere else on this forum (if I remember correctly) somebody experimented with differing numbers of scoops and some people got slightly different results. With my own testing, I found that it didn't seem to matter at the chlorine levels I was testing, but as a general rule I think it best to follow Taylor's instructions as can be seen at this link (http://www.taylortechnologies.com/products_instructions.asp?Type=Number&Number=5811) for the K-2006 kit.

Your higher TA is perfectly fine since you've got a vinyl pool so can have lower CH (which you have). The only issue with higher TA in your situation is a tendency for the pH to rise, but you don't see that because you keep your pool covered (with a solar cover) and probably don't have aeration features (fountains, waterfalls, etc.). If you had an SWG, then the higher TA would likely cause a very large rise in pH.

Richard

[ivyleager]

FYI,

I just purchased reagents and DPD-FAS powder directly from Taylor, which I would recommend over going thru this site. I received them in 2 days!

Anyway, the scooper for the Taylor powder is TINY! I can see why their directions may state to use 2 scoops. It's MUCH smaller than the one included in the poolsolutions kit.


CaryB

[huskerfan]

If I read it correctly the Taylor instructions say to use 2 scoops of DPD powder regardless of whether you're using the 10 or 25ml line. The directions pasted inside my PS233 Testkit from Ben says to only use 1 scoop- but only gives the directions for the 10ml line. With now knowing the dipper is a lot smaller from the Taylor kit, that would make up for the one scoop difference on the 10ml line, but I was still told to only use 1 scoop on the 25ml line too. Obvious thinking would be to add 2 scoops for the 25ml line - but was told to still just use 1. Sometime I'll do it both ways, after my chlorine level comes down. I actually just went and got my last sample for tonight, and tried the 10ml line both with 1 scoop and 2 scoops from Ben's test kit. Both readings were identical for both TC and CC: 16 for TC and .5 or under for CC.

Also- referencing the CYA with both listed above - Taylor's says to cap & mix for 30 seconds, while Ben's says to cap, mix, and wait 30 seconds, which I take as letting it rest for 30 seconds after you mix it before pouring it into the tube. Maybe I'm interpreting this wrong?? I have been known to be wrong once or twice in my life, lol! So which is correct - or maybe it doesn't matter either??

I prefer to give my business to Ben, but if in a pinch it's nice to know the reagents can be gotten elsewhere quicker. Please note too: my DPD powder is med. gray from last year and some of my other reagents 2 years old, so realistically my readings might be off because of that. But a post I read where Poconos did some experimenting with darker out dated DPD powder I believe, if memory serves me correctly, says he got the same results with the old and the new.

Wish my cc would have dropped more- but maybe my pool will never get to 0cc. The last summer and 1/2 (this is my third season with our pool) I always had .4cc, never 0. I have a lot of trees on two sides and a cornfield a little ways away from 1 side. Nebraska gets a lot of wind which blows around pollen and dust. I'm pretty anal at keeping my pool very clean, but you can't always see all the contaminants either. We haven't died yet- and our water doesn't smell and is crystal clear and feels good, so I guess I'll keep doing what I have been doing and just enjoy it :). Happy Swimming all.

[chem geek]

One possibility is that your weekly use of PolyQuat 60 results in measurable CC. You might try measuring it soon after an application and then a week later before another application and see if you notice any difference. It is known that chlorine will react with PolyQuat 60, but I do not know if it will show up as CC in the chlorine test. We do know that non-chlorine shock (potassium monopersulfate, KMPS) shows up as CC so it is quite possible that PolyQuat 60 in the presence of chlorine also shows up as CC.

As for the number of scoops and the CYA mixing, I suspect it won't matter very much. For the chlorine test you just need to have enough powder to develop enough color even for low levels of chlorine. The titrant will make it colorless regardless. It's just like indicator drops where color will shift -- it's only an issue if you are measuring the intensity of the color with a colorimeter as opposed to seeing a shift in the color (red to blue for CH; pink to colorless for FC; green to red for TA). The CYA test just needs mixing and then time to develop so continuing to mix or letting it sit should work either way so long as it is thoroughly mixed initially.

Richard

[Pool in Carolina Blue]

If I read it correctly the Taylor instructions say to use 2 scoops of DPD powder regardless of whether you're using the 10 or 25ml line. The directions pasted inside my PS233 Testkit from Ben says to only use 1 scoop- but only gives the directions for the 10ml line. With now knowing the dipper is a lot smaller from the Taylor kit, that would make up for the one scoop difference on the 10ml line, but I was still told to only use 1 scoop on the 25ml line too. Obvious thinking would be to add 2 scoops for the 25ml line - but was told to still just use 1. Sometime I'll do it both ways, after my chlorine level comes down. I actually just went and got my last sample for tonight, and tried the 10ml line both with 1 scoop and 2 scoops from Ben's test kit. Both readings were identical for both TC and CC: 16 for TC and .5 or under for CC.

Also- referencing the CYA with both listed above - Taylor's says to cap & mix for 30 seconds, while Ben's says to cap, mix, and wait 30 seconds, which I take as letting it rest for 30 seconds after you mix it before pouring it into the tube. Maybe I'm interpreting this wrong?? I have been known to be wrong once or twice in my life, lol! So which is correct - or maybe it doesn't matter either??

I prefer to give my business to Ben, but if in a pinch it's nice to know the reagents can be gotten elsewhere quicker. Please note too: my DPD powder is med. gray from last year and some of my other reagents 2 years old, so realistically my readings might be off because of that. But a post I read where Poconos did some experimenting with darker out dated DPD powder I believe, if memory serves me correctly, says he got the same results with the old and the new.

Wish my cc would have dropped more- but maybe my pool will never get to 0cc. The last summer and 1/2 (this is my third season with our pool) I always had .4cc, never 0. I have a lot of trees on two sides and a cornfield a little ways away from 1 side. Nebraska gets a lot of wind which blows around pollen and dust. I'm pretty anal at keeping my pool very clean, but you can't always see all the contaminants either. We haven't died yet- and our water doesn't smell and is crystal clear and feels good, so I guess I'll keep doing what I have been doing and just enjoy it :). Happy Swimming all.

Husker:

I am having a similar problem here in North Carolina. Last year it was not a problem keeping CC at zero. Today, despite shocking to 18 ppm with bleach last night, my CC is still at .4. MY CYA is roughly 20 so I am sure my shock level was high enough. I have noticed an inordinate amount of pollen this spring so maybe that has something to do with it.

[huskerfan]

In reading some posts and emailing with Matt 4x4, I decided to try overshocking, and it worked. I brought my chlorine level up to 29 and held it there for one week and my cc finally broke. It didn't do any damage to my liner and my suspended iron (we have well water used to fill and treated with pool magnet) gave me no problems. Don't be fooled in thinking just because you have a crystal clear pool everything's ok. Mine has never been anything but crystal clear, but now I can finally say it's totally clear. I was a little leary raising it that high -- but glad I followed through with it and got rid of whatever it was lurking! Thanks for everyone's help and posts. I too ordered my testkit refill supplies from Taylor directly. It takes a lot of 0871 to test your chlorine and cc levels when you're at 29 chlorine!

[chem geek]

Donya,

I'm glad you got your CC cleared up. Did you ever try measuring CCs soon after adding the PolyQuat and then just before adding it again a week later? Alternatively, if you start using PolyQuat again, let us know if you see the CC showing up again. If you do, then that would be a good indication that PolyQuat may measure as CC. If you don't, then you may have had some persistent combined chlorine that high FC levels got rid of (the high FC levels would very likely get rid of any remaining PolyQuat as well).

Richard

[Pool in Carolina Blue]

Donya,

I'm glad you got your CC cleared up. Did you ever try measuring CCs soon after adding the PolyQuat and then just before adding it again a week later? Alternatively, if you start using PolyQuat again, let us know if you see the CC showing up again. If you do, then that would be a good indication that PolyQuat may measure as CC. If you don't, then you may have had some persistent combined chlorine that high FC levels got rid of (the high FC levels would very likely get rid of any remaining PolyQuat as well).

Richard

Richard:

I just did this and yes, the polyquat was the culprit in my pool. I thought it was the pollen and other airborne debris.

[huskerfan]

Argggggggg- forgot about checking that... but... with no solar blanket on my pool at all - I got my cc down to 0, and it stayed at 0 about 2-3 days while my chlorine level dropped back to normal. Then when my chlorine level was around 6 I put my solar blanket on our pool later in the evening. The next morning I had cc of .5 again (had not added any poly60 at this point). The solar blanket was washed off at the end of last season - then just rolled up on the reel and bungee corded on there and left uncovered over the winter. When I unrolled it to put it on my pool for the first time this year, there was some water accumulated in the roll at the bottom -- so I rinsed off where it was as it had a brownish film on it. So... something from my solar blanket or the pool being covered brought my cc from 0 to .5. I took the solar blanket off yesterday for about 3 hours or so, and pulled a sample to check last night before putting my solar blanket back on or adding my bleach, poly 60, and a tad bit of muratic acid as I've been heavily aeriating to get my alkalinity down. Still checked .5cc. Added my chemicals (bleach, 7oz poly 60, muratic acid) and covered it back up.

Checked it today - cover hasn't been off yet... also -- got my refills for my testing kit from Taylor just a bit ago -- so used all new reagents to check it.

FC 4.2 (using 25ml line)
CC .6
TC 4-5 (hard to tell which)

re-tested again using the 10ml line:
FC 4
CC .5

ph 7.3 to 7.4
alk 150-160 (was previously 180-190 before aeriating)
cya 25-30 (has been testing around 45ish with my old reagent)?? Even tested it a second time with the new reagent to make sure.

So for now will just monitor my levels and keep my chlorine around 5.

Later I'm gonna recheck my cya again - first using my old reagent, then the new again. I'll make sure and keep an eye on my cc in reference to when I added my poly 60 this time and will report back.