Continuously getting Moisture In Clutch Fluid.
 

So I flushed out my clutch fluid twice so far, first after I boiled the fluid at my 2nd track day with the stock fluid, I had already switched out the brake fluid to RBF 660 earlier that year. Switched out out the RBF660 never had a problem with boiling the fluid. A year later I got a brake fluid tester to see if I should replace the brake fluid which was about a year old. I tested the brake fluid and it measured about 2% water content. Since it was the same fluid I decided to test the clutch fluid as well which was only 6 months old, it read >4%! So last year I had the brake and clutch fluid flushed and put both RBF600 in. Last night I got the tester out again and it read 1% on the brake fluid and >4% on the clutch fluid.
Why would so much more water be getting into the clutch fluid system? I know CSC maybe failing but then it would have been failing for over a year and almost 10k miles with track days and dragon runs.

There's always a chance it got moisture in it when you did the change. The fluid can suck up moisture pretty quick on a humid or misty day. Years ago I had to add some AP racing BF on a misty day and could see a pretty significant interaction with the air while the filling the reservoir. It almost looked like the surface was boiling. Also the SST braded lines usually have a better moisture barrier because of the internal materials used. It could be a factor if you have SST brake lines and standard clutch lines. Seems like a lot of moisture in a short period of time. Guess that's why they say to flush it before every track day.

Yes I do have SS brake lines and stock clutch lines. That could be it, I do change both brake and clutch at the same time so I don't think it's environment related.

I'd check the reservoir cap and anything else that might allow air/moisture and not let brake fluid out.

Dont forget the clutch fluid system is also a lot smaller in fluid volume so it will get more moisture faster.

If you dont want to keep doing a full flush, you could just siphon out the fluid in the reservoir and put in some new fluid it will cycle through eventually and you can repeat that to get most of the moisture out.

I also have a spare ss clutch line if you want it Pete. I have no use for it since I converted to the z1 csc elimination kit.