Silt on Steps and Outs

[waterbear]

The pool is:
13,500 gal gunite
Aquarite Salt/Chlorine generator
DE filter, Polaris 280
Waterfall (2~3 ft) and a bubbler on a tanning ledge. (constant aeration)
There is moss rock copping around half the pool and standard flag stone around the other half.
The pool is 3 years old (about to start the 3rd season)

My chemistry has always been pretty good (some issues this year, but I'm getting those under control)

pH 7.5 ~ 8 (constant raise in pH over the week, add muriatic to lower)

Pretty much standard prodedure with a SWG

TA 100 ~ 150 (add muriatic in columns to lower)

Your TA numbers look fine but if you want to lower them check out this thread. Adding a colum of acid doesn't really work effecienly!
http://www.poolforum.com/pf2/showthread.php?t=191

CH 200 ~ 400 (It's been on the raise lately, still trying to figure that out)

Are you by any chance shocking with Cal Hypo? Have you tested your fill water's hardness? Some flagstone has a high calcium or iron oxide content. Your numbers look fine in that range also.

TC/FC 1~3, CC 0
Salt 3000 (from the Goldline controller)
Just got my Taylor TK, so I never tested CYA before this season.

From the first day, I've had a constant depositing of brown silt or very fine dirt on the steps, the tanning ledge and the outs.

Possibly dead moss? Step and ledges are notorious for not having the greatest circualtion to move stuff off of them.

I've attributed this to new-pool dirt on all the moss rock, or maybe it's being blown in, but it's pretty constant. I need to sweep it off every couple of days.

Now the pool is several years going and I don't think I can blame dirt from fresh moss rock anymore. The only other source is it being blown in

-OR-

is there another reason?

Just some ideas for you to consider. You might want to post some more exact numbers from your next test with the Taylor kit. It will help know just where your pool is right now.