[taizentek]

I recently asked what stain to use for my Ipe and massandruba deck. I decided with the help of many on this site to go with woodtux. Thanks for that advice but now I need more help.
A little history is in order so that you know what stage I'm at.
I built an Ipe and massandruba deck two summers ago. I let a not so professional finish it with messmers. He used twice as much as necessary and didn't wipe off the excess. (You get what you pay for!) Anyway, so much for my two tone deck. Everything came out super dark. Last fall I rented a drum sander and sanded the whole deck except the railing. It came out good, I evened off the boards which were pretty cupped and the color was back to the way it was originally.
Yesterday and today I used RAD on the railings and the deck with my pressure washer. I sanded the top rails of my railing first as I did not do them last fall. Most of the top rails (ipe) came out good but one of them and many of my floor boards did not come clean. They remained dark. I used the rad as directed and tried it at a stronger dose as well. I was able to sand some of the stubborn dark spots out on the steps. I also had some wolman deck stripper from last year. I gave that a shot on one board that I had already stripped with the rad. It got the ipe back to the original color. So with my bright idea I decided to use it on the entire floor. Some of the boards it worked on and some it made real dark. Also, I know trhe directions of the rad say to make sure you rinse it well. As many times as I go over the deck boards, it still suds up. Will the brightener nuetralize this or do I have to keep rinsing. (i've spent the entire day on about 300 sq ft.)
Can the dark spots be tannin that has been drawn out by the stripper?
How can I get rid of them?
I am sorry for the long post but I could use some advice. I took a few pictures but I haven't had a chance to upload them. I will try later.

Thanks for your advice.
Mike