Trouble getting CC to zero.

[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 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.