Spot stains

[LPCPool]

So, after overcoming some iron stains at the water line using the AA method, I'm trying to attack a couple of spot stains at the bottom. I'm almost 100% certain that these are metal stains also, but not sure what kind since they didn't respond well to vitamin C. They're roundish, greenish orange in color and range between nickel and half dollar size.

I was wondering what I could use to apply some MA directly to them without having to do any draining? Or, perhaps, someone could offer some other suggestion as to how I could try to get rid of them?

 

[JasonLion]

Try resting a trichlor tablet directly on a stain for about 10 minutes and see what happens.

 

[LPCPool]

I tried it on a couple of different ones just to make sure and there was no change

 

[JasonLion]

There is a way to apply muriatic acid, but at this point I'm not at all sure it will work. I am unclear on what the stains might be if trichlor has no effect.

If you want to try MA, get a piece of PVC pipe several feet long, place one end of the pipe over a stain and pour a little muriatic acid into the other end of the pipe. That will localize the effect right near the lower end of the pipe, right where the stain is.

If that doesn't work, I am out of ideas.

 

[LPCPool]

I appreciate the input, Jason.

Not sure how well that'd work since most of the more prominent ones are on the deep end slopes just before the bottom. If I could hold the pipe in place and pour the MA down it, the time on stain would be negligible. I was really hoping that there was an applicator for this sort of thing. In the end, it doesn't really matter if it's MA or something else.

As far as what they might be, I inherited the pool 2 years ago. Towards the end of the first season, the first 2 showed up. At that time, I had a pool service come every 2 weeks since I didn't feel comfortable handling things on my own yet. They sort of shrugged when asked. Supposedly they tried a spot treatment. Ultimately, they chalked it up to thin spots in the plaster and reaction to metal ribbing and the high pH due to the SWG.

As I mentioned earlier, at the beginning of this season, I had an iron staining issue that I posted some questions on (http://www.troublefreepool.com/threads/75221-Ring-around-the-collar?p=647270#post647270)

Doing the AA treatment, took care of all the new stains, but it had little to no effect on the old stains that I'm trying to take care of now. I guess I could go through the whole exercise again in the hope that it would chip away at them. When I tried to apply some vitamin C tabs directly to them, it really didn't seem to have any effect - at least, not as dramatic as when I tried it on the new stains. It's kind of hard to judge when you're looking through 8-9 feet of water.

I have a kit that tests for copper and iron. After the AA treatment and before I added the sequestering agent (Jack's Magenta), it showed that I had .3 PPM iron and .2 copper. I've been diligent about keeping up with a maintenance routine with the Jacks, keeping the pH lower and not letting the SWG build up too much Chlorine too fast. I even went and got some of the CULator pads. The last time I tested, it showed 0 copper and .1 iron.

So, my guess would be iron (that's had a chance to settle in)

Since I'm about to embark on the last B in BBB (boric acid in this case), I wanted to tackle the stain issue before moving forward.

Given all the above, should I try the AA treatment again, or...??