Metal in pool

[doriec]

I recently added 2 qts. of metal out to my 27,000 gal. pool. It cleared up the stains beautifully. Then the water clouded up and turned green so I shocked the pool. The ph fell to 6.8, the water turned green, and it took 27 gal of bleach before the FC remained steady. The ph fell to very low levels. After reading the posts, I can see my mistakes. My questions are these:
1. I need to pour in more metal out after lowering the ph and FC levels. How much more can I add? Keep in mind that I already added 2 qts before my problems occurred.
2. Does the filter expel the old metal out and sequestered metals when I backwash? Or do they stay suspended in the water as the filters returns the water to the pool?
3. Do I always have to keep my water's ph low to keep the metals from "dropping" out?
4. Will the metals "drop" out again whenever if I have to shock the pool to get rid of CC?
I have a salt pool. I fill with 1/2 well water (with lots of iron, I am sure) and I/2 with softened water because of hard well water.
My FC is 5
CC 0
ph 7.4
TA 150
hardness 250
I use bleach to shock, borax to raise ph, and acid to lower the ph.
Thanks for your help.
Dorie

[aylad]

I'm not the metals expert around here, but I can tell you that high pH and high Chlorine are going to cause the metals to start staining. You do need to keep the pH fairly low, but if it's a vinyl pool you don't want it to be below 7.0, because that's TOO low and can cause damage to the liner. If you need to shock the pool, watch it as the chlorine rises, and if you start seeing discoloration, add the metal out then.

I'm sorry I don't know how much to add or the answer to your other questions, but Marie (Mbar-- the resident metals expert other than Pooldoc) should be by soon and can help you further. IN the meantime, I encourage you to read through the other posts in the metals forum, and particularly the stickies, because you'll probably find some of the information you need to understand metals in there.

Welcome back to the forum!!

Janet

[doriec]

Thanks, Janet. It is nice to be back.
I forgot to mention that when I used metal out last time, aside from the cloudy pool, algae, and screwy chemical levels, my CYA level fell to 0. Why is that?
I am going to try the metal out again. This time I am going to be sure that I have low ph and FC levels before I add it. I hope someone out there can tell me if sequestering these metals will the filter to get rid of them. If not, it will be a game to keep the chemicals perfect to avoid the staining again.
Dorie

[aylad]

It's always going to be a game to keep the chems right. The metal sequestrants hold the iron in suspension in the water, but they don't actually remove them. There is a thread started by a new user, labdi01 where she talks about some sort of filter she made that actually removed the iron from her water. It apparently worked for her, but I don't have enough experience with it to know whether to recommend it or not. You can read through it at http://www.poolforum.com/pf2/showthread.php?t=9706 and it might give you some insight. Also, read through Pooldoc's post (#22) at this thread http://www.poolforum.com/pf2/showthr...?t=9660&page=3 and see if it helps.

Janet

[doriec]

Janet,
I read the last post you mentioned--very good. It answered some of my questions. Apparently, sequestered metals will filter out. That is good news. I still don't understand why the metal out drops the ph and eats up chlorine. Maybe someone can help with that one.
Thanks,
Doris

[doriec]

I am still having problems with staining. This is what I have been doing to correct the problem.

I lowered my ph to 7.2, allowed the chlorine to drop to .5, and then poured in the specified dose of metal out. The stains dissappeared almost immediately. For two days I ran the filter and backwashed each day. Then I allowed the chlorine level from the salt generator to rise to 1.5. and the ph to 7.4. Within hours, the stains came back. I lowered the ph and chlorine again, and the stains disappeared again. I am now running the pool and backwashing again. How long will this process take before the stains stay away? My pool numbers are good, except for the alkalinity which is 135. I am trying to get that down through lowering the ph and aeration.
Thanks for helping me.
Dorie

[waterbear]

Janet,
I read the last post you mentioned--very good. It answered some of my questions. Apparently, sequestered metals will filter out. That is good news. I still don't understand why the metal out drops the ph and eats up chlorine. Maybe someone can help with that one.
Thanks,
Doris

No, sequestered metals do not filter out. They are dissolved in the water and in an ionic form. Being sequestered means that they are not chemically reactive so they won't be oxidized and either color the water, deposit as stain, or precipitate out. Remember, the definition of sequester is to 'set apart' or 'put into seclusion'. Metals that have PRECIPITATED out of solution are filterable but they usually just redeposit on the pool as stain again.
If you are referring to my post about chitosan, remember I said that I do not know how effective it is, just that it has been documented that it can combine with metal ions and then filter them out. I do not believe it is a very effective process or someone would have already marketed it as a metal remover.