slimy, gelatinous strings of goo ruin a good dip.........

[PoolDoc]

I am convinced the staining is from the gigantic amount of borax I put in the pool. I should probably have used the brush to move it around.

Borax doesn't dissolve instantly, which is why we try to always tell people to add it via the skimmer. However, borax itself won't stain anything. What probably has happened is that the iron in your pool water was precipitated out when you added the borax that way. I've already covered the topic of iron removal pretty fully.