Stains will not go away

[jovans]

New pool owner here just bought the houses last winter and have been trying to learn everything I can about my pool, as this is my first experience with a pool. I have since switched to the BBB method after getting pool stored to death already. The pool is approx 13000 gallons and is an above ground vinyl liner. I have a 48 sq ft de filter and a hayward single speed 1.5 hp pump. So here is the problem, about a month ago I went to the pool store to have my water tested, this was before switching to the bbb method, they told me I need to shock my pool again and that my ph was low and that I needed to add a whole **** load of soda ash. no warning or anything. I believe it was 10 lbs of soda ash. They had me add it all at once at the same time I shocked it. Following this I noticed that my pool started to change color a little bit, and I didnt think much of it. Until the next morning My pool looked horrible. Everything was brown and just looked terrible. However the water was still clear. I headed back to the pool store and the told me it was obviously an algae. So they sold me more shock to shock the heck out of it and copper algaecide. neither of these processes had positive results. that is when i started doing some more research online and had come to the conclusion that it as a metal stain, which we do have well water so its not unheard of. and somehow the previous pool owners had never had a problem in the previous 10 years. So back to the pool store i went and got 5 lbs of glb stain magnet and some sequasol. dumped the stain magnet in and I watched the stains disappear before my eyes. I was relieved and thought that i had beaten the problem. added the sequasol to help sequester the metal. days later did a complete refresh on the de filter. 2 days later the stains started to reappear again. so i went back and repurchased the same stuff and hit it again and it looked great, again. well now the stains seem to be starting to reappear and i am defeated, i don't know what to do. and i cannot keep purchasing 100+ in extraneous chemicals each week. as of now these are my levels.
FC 6
PH 7.2
TA 90
CH 200
CYA 80

any help i can get to help solve this problem would be much appreciated.

 

[JasonLion]

Welcome to TFP!

First, stay away from copper based algaecides. They can cause stains that can not be removed from vinyl pools. For that matter we don't recommend the use of algaecides except when doing stain removal.

The stains sound like iron stains. I doubt you had algae at any point recently. Stains returning means you are either not using enough sequestrant or are using an ineffective brand of sequestrant. Sequestrants based on HEDP, phosphonic acid, or phosphonic acid derivatives are the most effective. ProTeam's Metal Magic and Jack's Magic The Pink Stuff (regular), The Blue Stuff (fresh plaster), and The Purple Stuff (salt) are some of the top sequestrants. You can also find many other brands with similar active ingredients, some of which are noticeably less expensive.

 

[jovans]

any ideas on what would have caused the metals to form on the liner, as the previous owners had never had this problem according to our neighbors.