ascorbic acid treatment

thanks for the info. on removing stains with ascorbic acid. it worked well. seven and ahalf pounds (80,000 gal. pool) removed all stains from vinyl liner, pump baskets, all plastics are back to original white colors, and i am sure that the insides of my sand fillters are clean as well. pool went from a green color to a nice blue color (pos. copper issue) as metals were released back into the water. i used sequestering agents as instructed. the pool went very cloudy (milky look) and my TDS readings were 5000 plus (normaly around 1500). i removed about 55 to 60,000 gal. of water to pool and is still showing cloudy and blue, but TDS is down to 3000. incoming water is at 150 to170 total alk. and pH is at a7.80 to 8.00. calcium hardness is at 360. i use bromine and shock with potassium monopersulfate (both are acidic with low to no calcium i think). so now the pool has about 60,000 gal. of fresh water, bromine at 4ppm and a cloudy pool but still blue. so i decided to shock with monopersulfate and use some clairifier. came back the next day and the pool is green and all the staining has come back on the liner. it is amazing on how the staining and water color changed over night. i am going to redrain the entire pool, clean the vinyl liner with an ascorbic acid-water mix, which i know will take the stain off, flush the metals down the drain and refill the pool. i guess i probably made some mistakes on this stain removal project. again, i think this process is great and i will be using it in the future. staining is a big problem with this pool and out of all the processes i have tried, this is the best. there is no better process that i have found for this perticular pool. if anyone has any info that could help clear up any issues that i had or any useful tips in general regarding this i would sure love to here it...thanks for your time....poolteh..

I'm not sure you made any mistakes, though it sounds like you didn't complete the process, at least at first. There are 3 functional steps: re-dissolve the metal stains, treat them to keep the metals in the water and then EITHER remove the metals from the water (CuLator or calcium adsorption OR

We've gotten several reports of sequestrants clouding the pools they were used in. This result is not consistent with the old Dequest / Monsanto data I have on HEDP. I'm not sure if the problem is that the products are not HEDP, or if they have something in them besides HEDP, or if the Monsanto data is in error.

Can you tell me EXACTLY which sequestrant you used, and how much?

Also, have you identified what metal is staining your pool (sounds like iron) and where it's coming from? Have you done the bucket test on your incoming or fill water, to make sure that it's not contaminated with iron or something else?

Hi pool doc.thanks for the response. The sequestering agent is Sparkle Conquest, manufactured by Alden Leeds Inc.. I added one quart per 20,000 gal.. total added was four quarts for 80,000 gal. I had an independent lab do water test on our supply water and pool water. The lab says that mg/L is the same as ppm (parts per million). supply water test is as follows: iron= not determined, magnesium= 5.38 mg/L, copper= 0.134mg/L, and manganese= 0.0232mg/L. pool water test is as follows: iron= not determined, magnesium= 35.8mg/L, copper=0.0047mg/L, and manganese=0.0111mg/L. what is the bucket test? I was not able to do direct reply and had to start another thread…thanks for your time…pooltech..

Well, your test runs tell you that neither copper nor manganese are the problem . . . which probably means iron is.

The metals bucket test is described in this forum section (Dealing with Stains & Metals, . . . and 'Minerals' & 'Ions') and allows you to test for staining metals in your water in a non-quantitative, but more reliable manner.

The 2004 MSDS I have for Alden Leeds Conquest reports that it *was* 60% HEDP, so I assume it probably still is. You might want to call A-L and ask, though. 1 gallon of 60% HEDP in 80,000 gallon is pretty high, and could cause problems with calcium > 300 ppm.

(At least for water, your lab is correct that 1mg / L = 1 ppm.)