If metals make water green, will they make CC high?

[dborn]

Hi all,

In the process of opening the pool. I've been shocking with granular chlorine (because I have alot on hand) as opposed to liquid chlorine.
After 5 days, water has cleared but keeps a "lemonade green" tint no matter how long I shock. Last check, FC = 4, TC > 10
It's probably metals (just received my TFT-100, copper, iron test kits today) but not sure yet.
If the metals are oxidized by the chlorine, would that produce high CC? (I'm thinking yes).
Should I persist shocking no matter what, until the CC is almost 0 or should I stop shocking until I can test for the metals and add sequestrant?
I figure keeping metals oxidized in the pool water for several days can't be good for staining the pool (fibreglass)

I will soon report all numbers with my new test kits to help you guys out,
Daniel
P.S. Haven't done anything but add chlorine so far...

 

[linen]

If the metals are oxidized by the chlorine, would that produce high CC? (I'm thinking yes).

No they do not.

Get a full set of test results with your tf-100 and post them.

 

[Richard320]

Recent thread where people describe the same phenomenom. In some cases, it goes away. shocked-the-pool-now-a-green-tint-t58313.html

 

[dborn]

Thanks for that link.
I had the same green tint opening last year and when chlorine dropped back to 0, water was clear. Add a cup of chlorine: green again until it drops.
I then proceeded to use a chlorinator, keeping FC around 1.0 on top of an ozonator. At the end of the season, started noticing pool had an even beige tint below the waterline. (thought it might have something to do with the green water when high TC situation that was left unresolved?).

Now the green tint again, will test for everything as suggested and will report back.
I temporarily stopped shocking until I understand what's going on. I'd like to have my water clear and my pool unstained if I can...
I' m going to be installing my new Stenner pump soon and bought several cases of pool liquid chlorine (stored in the dark, cool basement) and I'm gutting out the chlorinator. That thing never worked well and shot my CYA levels way up in one season!

 

[dborn]

Well, as promised, here are my complete test results:
I've recorded all results from the TF-100 and compared them with my LaMotte ColorQ 7 to see how good/bad it really is.

First of all, the Taylor metal tests:
Copper: 0ppm (no color, clear as water)
Iron: 0ppm (no color, clear as water)

The other parameters, I'll compare TF-100 / ColorQ for each:
DPD FC 1.5 / CQ 1.93
DPD CC 10.5 (TC 12) / CQ 8.38
K1000 CL 5+ (I didn't try diluting with distilled water to double range)
K1000 PH 7.8 / CQ 7.7
TA 100 / CQ 104
CH 250 / CQ 124 as always, the CQ is really poor here
CYA <20 / CQ 8

So, I think I see no reason to not continue the shocking until CC < 0.5
Water is still green as lemonade and fiberglass pool sides and bottom are somewhat brownish colored... :?

Now, I think I want to:
Continue shocking, maintaining FC around 10
bring the TA towards 80 & PH towards 7.2 (has a tendency to be high, probably worse now with liquid chlorine)
bring the CYA towards 20 (no more than 30)

What do you think?

Thanks,
Daniel

 

[frustratedpoolmom]

Leave the TA and PH alone until you are done shocking. Target 30 for your CYA. Adjust the shock level accordingly.

 

[duraleigh]

What do you think?

I think you are on the right path. I would suggest you ignore your pH and TA (and CH) for now and then you can fine tune them later when your pool is crystal clear.

CC's that high indicate a good deal of contaminants have been in your water and you may need to keep your FC up fo quite a while until the CC's get to less than .5 ppm.

 

[dborn]

Thanks all,

I feel reassured now that I won't be aggravating anything if I need to maintain shock levels up for a while.
I'll add a bit of CYA to target 20 at first, shock and then fine-tune the rest after.

Cheers,
Daniel

 

[linen]

Do you know what your cya level was at the end of last season? If it was higher (significantly) then it is now, the CC is likely ammonia and will take a bunch of chlorine to break down.

When you say the water is green lemonade, is it cloudy as in you can not see the bottom cloudy?

Your plan sounds good.

 

[dborn]

Follow up on my story:

I kept shocking the pool until the green was all gone. Well, it was metals because then my fiberglass pool was a stained brown mess. Poured in some metal stain remover/sequestrant from the pool store (figured I had nothing to loose) and lo and behold, the pool returned to it's glorious original white and water was clear.

After three weeks of not adding anymore sequestrant, water was back to lemonade green!
Poured in some more sequestrant (only half from the first time since the fiberglass wasn't stained yet) and now it's back to nice and clear.

Currently trying to filter it out with a submersible pump and a MetalTrap filter http://www.askalanaquestion.com/METALTRAP.htm
Sure hope no one is going to tell me that these things don't work...

 

[dborn]

Here's a followup to my ongoing story:

After having filtered the pool water through the MetalTrap filter for a good 9 days (more than twice the water volume), the sequestrant finally stopped doing its job and I know this because the water went back to green again.

I decided I needed to get to the bottom of the causes for the green water so I had the pool water analyzed professionally (not at the pool store) and the report came back with .4 ppm iron and .01 ppm manganese.

Ordered some more MetalTrap products (stain reversal kit) that I'm still waiting for. In the meantime, I had bought a 1 micron pre-filter at the same time as the MetalTrap filter so I decided to give that a try while I wait. Well, after less than a day (about 75% of the water volume through the filter), the water is clear again and the filter is pretty brown (meaning it's definitely filtering something out of the pool water).

I don't know what to think here. Why did the MetalTrap filter not filter any of the iron out while the inexpensive 1-micron filter seems to be resolving the problem on its own. I'll have to get the newly filtered water analyzed again to see if it still has .4 ppm of iron in it or not. If the problem was not dissolved metals, what was it? metal particles? something else?

I think I'm going to wait before treating the water further with the upcoming metal treatment products just to see how it's going to evolve (or not).