impala1ss,
I think that it possible that the numbers supplied by your pool store could have been incorrect unless they were using a Taylor test kit, or the one used on this forum, and all the chemicals were still current. If using Taylors you can call their number, 1-800-837-8548, read out the codes and they will advise if they are still usable. Without a good test kit you are really walking in the dark as regards the pH.
If you did the AA treatment at too high a starting pH, say above 7.3, the AA may not have been as effective as it should be. If the AA was old, especially if it were older than 2 years, it would be very ineffective against stains, what was the good by date? If the pool is heavily stained, then 2 lbs per 10,000 gallons would be better, but ultimately you did use 2 lbs. And the Vitamin C (AA) tablet test showed no change to the surface, but how old are those tablets?
I am not sure what the MSDS sheet states for the ingredients are for "Suncoast Iron and Cobalt Remover", if you cannot get a MSDS for it I would question whether you should be using it. I could not find one.
You should use an HEDP sequestrant such as "Jack's Magic Purple Stuff", or "Metal Out". I believe that 2 bottles of HEDP in the AA treatment initially, is better than one. Have you been using a sequestrant? If so it is possible you have phosphate scaling. Did you test for phosphates? Maybe copper staining or scaling from a pool heater or old solar system, is that possible?
It seems as Richard320 mentioned you may most likely have scaling issues and he supplied a reasonable solution for persons fit enough to undertake it, but it also seems you do not want to be scrubbing with a wire brush. If this is what you meant by "Any other suggestions?"
Just recently I used a slightly modified AA method to remove both iron and other metals (AA only sequesters iron)
and scale, it was very successful, and did not require wire brushing. I believe it also removes the physical iron and other metals from the pool and not, as the AA method alone does, just the stain which sequestrates only iron into solution for possible later re-staining if the pH rises above 7.4.
The iron can be backwashed out in this revised method. As the procedure is very new, and viewed as experimental , so far only one other person has reported back on its use, but it seems they were satisfied. The link on how to do it will follow, but if you do use that method, please report your results to that post,, many people never do.
The fact that some iron was removed in your initial attempt is good as far as this revised treatment is concerned as it likes to have both iron and orthophosphates, or at least one ingredient, as catalysts to help in the removal of scale and metals .
In my own case the revised procedure removed stains AA was never able to remove, and I have done a lot of AA treatments over the years.
Please note if you have copper stains I have not covered that yet but will get to it sometime soon. For copper it requires a high pH.
Here is the link go to the very bottom of the page and about quarter of the way up are the revised instructions, good luck:
http://www.troublefreepool.com/used...-removing-metal-stains-results-t56485-60.html