Ascorbic Acid Treatment almost got all the Metal

[JeffMatthews]

Pool was severely neglected by previous owners. Metal stained probably 30+% of the bottom.

Maybe 20,000 gallon pool. Plaster.

I used 2 lbs ascorbic acid, and it worked pretty good. 2 days later, I added another 2 lbs. It helped even more. I would guess it got about 85% of all the staining.

I found 11 lbs of ascorbic acid on line in ebay for $60. I expect to receive it in about a week.

I am thinking I will go at it with a heavy dose this time. Maybe to add 5.5 lbs all at once.

What do you think?

The next thing will be to keep the metal from re-depositing. I used Ram Metal Hold, but in looking around, have seen a few people say it is not nearly as good as Jack's Pink Stuff. Any thoughts on that? Also, will I need to keep a regular maintenance dose of any of these sequestering agents "forever?"

 

[Stuamurr]

Don't know about the absorbic acid treatment sorry, but I would guess as long as you are following the information in this thread ascorbic-treatment-to-rid-pool-of-metal-stains-t2298.html closely enough you shouldn't have any concerns.

Using a metal sequestering agent should not be necessary unless you have a donor which is adding metals to your pool, it's just an expense you don't need otherwise.

Regards
Stuart

 

[Swampwoman]

Actually, I believe the instructions in that thread specify that you do need to sequester the metal with a full dose to prevent the stains from redepositing, and then maintain the sequestrate to effective levels, because once the metal is in there, it will always be there until splash out and refill dilute it to a level whereby it's not inclined to stain. If you're so inclined and know your water source doesn't ave more than about .3 ppm of iron, etc., you'd be better off in the long run to change the water, even if that meant trucking it in. Constantly maintaining sequestrate like jack's pink will also mean having a high phosphate load, which is fine so long as you never ever let your chlorine drop. However, if you did let your chlorine drop, you'd have a lot of phosphorous to feed the algae

 

[Stuamurr]

I withdraw my statement :-/ apologies, as I am not familiar with the absorbic acid treatment I was not thinking about the metals in the pool already, and was opinioning in general terms.

 

[JeffMatthews]

No problem. Glad to finally see a reply. The 11 pounds of ascorbic acid came in. I was hoping someone in here knew something about what it would take to Overdose a pool with ascorbic acid. I feel like a heavy dose is in order, but don't want to do something stupid and regrettable.

 

[Stuamurr]

I regularly check the unanswered posts, to try and get them answered, even if I can only contribute a little to your question, it does get the post re-surfaced for others to peruse ;-) hopefully someone with the relevant knowledge will chime in forthwith.

Regards
Stuart

 

[Swampwoman]

No worries, Stuart -- I just didn't want him to re-precipitate the stains, which happens -- which I only know because I read just about every stain thread going

Jeff, I've only done a minor AA treatment, but am getting ready to do one in the cooler weather of autumn.

If you've read through the instructions and various posts on this treatment, I believe you will find the recommended amount to be closer to the 4 lb range for your volume -- so if you mean 4-5 lb at once, you're likely fine...but if you mean the whole 10 lbs -- I DON'T KNOW I'm not sure what happens if you use MORE than the recommended amount at one time, but do remember that a) it IS a form of ACID, albeit a mild one and that b) water balance coming out of the treatment may be temperamental (mine was) -- so if you use MORE AA, you may have a harder time re-balancing your water, getting a chlorine read again (because you're to SLOWLY raise the chlorine...you're not to SHOCK for 2 weeks after the treatment...etc.) The AA WILL eat your chlorine. The chlorine will also try to eat your AA.

One impact to consider is what effect this will have on your CSI -- because you're plaster -- and I'm vinyl -- so I know nothing about this except that it is germane to water balance in plaster pools.

However, to beef up efficacy, if you have hard-to-reach or concentrated areas, I have been told that putting extra AA in a sock with some rocks and then targeting a heavy/or/historic stain area while also doing the treatment gives extra power to clear specific problem areas. So you may wish to give that a whirl.