Sequestration or Chelation??

[mbar]

I have used both sequasol and metal free. They are both good, so it doesn't matter which you use. I would add a good dose right after your fill - a little more than the bottle says. You will not have to do anything else when you close. I have already closed with stains and opened to a stain free pool - I don't know why, I can only guess, so don't worry about adding any sequesterer when you close. I would save the chemicals for next year when you open. Next year when you open, before putting anything else in the water add the sequesterer. This way any metals the were introduced over the winter or with your fill water will be taken care of. Then you only need to add it if you see any stain starting to form. If you see stain start, take your ph down to 7 - 7.2 and add sequesterer - it should lift the stains before they settle. Feel free to ask any questions you have

[Jakebear]

WOW --- this is great information and I do (almost) understand it.

Evan -- I've learned more chemistry since looking at this forum than I did at Brevard Engineering College (now FIT) in Melbourne back in the 60s.

Marie -- Keep the info coming about Metal Magic --- I'd just as soon have it settle so the robot can gobble it up and I can get rid of it. I do add quite a bit of water from the well so I guess the chelator or sequestrant will be a regular around here.

The free Cl has nearly quit dropping (2.8ppm) so I'm still waiting to add the Ascorbic Acid. Since the CYA is ~50 it could take a while based on Richard's half life explanations. Might have to add some sodium thiosulphate to lower it the rest of the way (Target = 1-2ppm)

Marie --- I'll have to look you up next time I make the run from Mahanoy to Shamokin. With all that coal leeche no wonder you get stains. Do you have to fight low pH too?

[mbar]

Mahanoy to Shamokin!!! We are neighbors Yep, the coal regions. I used to fight low ph, but this year for some reason my ph keeps rising It may be because it has been dry and I haven't used many trichlor pucks this year. I used to use them to keep the ph low so I wouldn't get stains. This year I didn't have any problem with stains so I have been just using bleach. I didn't check it today, but it probably is low from all the rain. What town are you from?

[waterbear]

I hope nobody minds me butting in here. I was wondering which would be a better product to use to remove any potential metals from my fill water when we refill after the new liner is installed. I have some of both GLB's Sequa-Sol and also Natural Chemistry's Metal Free.

Would one be better than the other on a fresh fill? Or should I use them both before I close for the winter? (not at once of course)

I want to make sure and get all the metals before they have a chance to do anything. I don't know the metal content, but it seems most of your opinions is more is better when it comes to preventing metal stains. This will be city water by the way.


Thanks.

First thing I would do is get the water tested for metals...if there are non present then don't add either one....If it ain't broken don't fix it!

[Jakebear]

Stain Free followed up with Metal Free (both Natural Chemistry products) per the directions on the bottle. It was dark till the metal free went in so I don't know if it got cloudy or not. I do know that the stain disappeared almost immediately when the Ascorbic acid hit the water.
We'll see the results in the morning.

The jug of Metal Free said to run the pump 72 hours then change DE (in my case) but I'm wondering how long I should keep the Cl down??? It does not say --- with the rain that we are supposed to get, I'm a bit nervous with it down around 1.5 ppm and CYA ~50. Any thoughts?? Phosphates are <100 so there isn't anything for algae to eat.

[mbar]

After 24 hours and if the stain is gone, you can start to balance the water. Your ph and alkalinity will be probably be low after the ascorbic acid, and you will probably have trouble keeping chlorine in the water. You can get your ph up to 7.2 and then start to add the bleach, add enough to take it up about 2ppms, waiting a little while and adding more until you reach about 4 or 5 for your cya. If you start to see stain forming, make sure your ph is no higher than 7.2 and add more metal free. You should be fine. Just don't shock for at least a week, maybe 2. You can keep your chlorine at the high side for your cya which at 50 would be 6-8ppms, but I wouldn't go higher for the 2 weeks. Feel free to ask any questions you have, good luck

[Jakebear]

The pH was ok this morning (7.5) TA down to 90 but FCl was 0.0 Added a bit of 6% (diluted first in pool water) to bring it up to ~1ppm and threw the robot in to keep stuff stirred up. The water is crystal clear and no apparent sediment on the seams of the liner where it always collects.

Still no rain but they are predicting 4-6 inches around here --- We'll see. I want to get CYA down to ~20 for winter then see where it needs to be for operations next year.

I'll keep you posted on the stains removal process.

[Jakebear]

OK Marie ---- How long should I expect it to take (getting the chlorine back up)??

I've read to bring it up slowly (1ppm per day) but at this rate it'll be next summer

Since I did the Ascorbic Acid and the Chelator, I have added Chlorine 8 times, and still the cl is <1ppm after a few hours. I suspect it is still consuming the Ascorbic Acid but after 3 days --- Enough already

One good thing --- We had 4.06 inches of rain, so my CYA is now near 40 So I should be able to go down a notch on Ben's BG Chart. I'm still shooting for between 4 & 6 just to keep it on the high side.

For those who care:
Water Temp 68 BRRRRRRR
pH 7.5 by titration
FC .4 ppm (FAS-DPD)
TC .6 ppm (FAS-DPD)
CC .2 ppm (FAS-DPD)
TA 80 ppm (by titration)
CH 240 ppm (by titration)
Phosphates <50 ppm
CYA = ~43 (turbidimetric)

[mbar]

Yes, the ascorbic acid is eating the chlorine. You can start to raise the chlorine to 6, just lower the ph back down to 7.0 - 7.2. You don't have to raise it so slowly when the ph is down. You should be fine - just keep adding chlorine to take it back to 6. As long as the chlroine is still being eaten, you won't get any stains - it won't be high enough long enough to stain You should be ok with the sequesterer. Don't worry so much, I know it's a pain, but you will get the hang of it. If stains do start to come back, just lower the ph and add more sequesterer - it will fade the new stains right away. It is just the embedded ones that need the ascorbic acid. My water temp is 68 too I am hoping to get some more swim season in, but it doesn't look too good - I get really sad when I have to close the pool Keep us posted on your progress.

[Jakebear]

Rather than leave everyone hanging, Here is the end of this saga. The stain is gone and the pool is back to normal.

It took a total of 6 days to bring the chlorine and pH back into range and keep it there without a lot of extra messing around. I have started using the maintenance dose of Metal Free so hopefully this process will not have to be repeated anytime soon (Never will be too early). So far I do not see anything "falling out" so I suppose it has been captured (hopefully forever).

Other than the cool nights and lack of sunshine, swimming might get back into the near future but the weatherman is not cooperating (65 high tomorrow) -- Pool temp is 79 today (my minimum is about 83).

Thanks again for the help and Information. This thread gets printed and filed for future reference.