Returning metals after ascorbic acid treatment?

[LaurenC]

Hi guys! I recently did an ascorbic acid treatment on my pool. Everything looked great for a couple of days and then the water started turning gray/green. It wasn't cloudy and nothing dispersed upon being brushed, so I concluded that perhaps I hadn't added enough sequestrant (I used HTH metal stuff). Within hours of adding more, the pool improved drastically and by the next morning (after running all night) it had returned to normal. Fast forward three days and my pool water has gone from perfect this morning to gray again! Anybody have any ideas? I figure I just need more metal sequestrant? But surely I shouldn't have to be adding it every three days??!!

specs:
28000 gallon salt water vinyl pool

FC 1.5
ph 7.0
cya 55
ta 50

 

[jblizzle]

Welcome to TFP!!!

What is the ingredient in the Metal Stuff? It may not be one of the better sequestrants as described here: Pool School - Metals in the Water and Metal Stains

 

[BoDarville]

Definitely recommend the sequestrants mentioned in that article. You'll still need to add some periodically, but it should be considerably less often compared to an inferior sequestrant.

 

[LaurenC]

Hydroxyethylidene Diphosphonix Acid. (I assumed this was HEDP which was one of the recommended ones??)

HTH Metal Control

 

[LaurenC]

Is there anything else you think that could possibly be going on?

 

[chem geek]

If you can't get the metal sequestrant to work or if its ongoing cost is going to be expensive then you could consider trying to use CuLator. Though it's had mixed results, whenever the company got involved with the user they've been able to resolve it so if you do go that route be sure to contact the company if you run into any problems. It's not cheap, but when it works it will remove the metal from the water. If you aren't getting metals reintroduced into your pool, then this is like a one-time fix.