Is this a normal about of corrosion for bus bars under a year old?

I rebuilt my pack 2 years ago cleaned the bars, SS nuts etc. Opened it yesterday, every single Neg post had corrosion with white a fuzzy coating on the battery post, the copper bars with blue corrosion front and back. The positive sides are clear. Here is a pic of another pack same age, all cells in parallel using plumbers strapping (steel and copper) as buss bar material for testing. Max charge on my PS is 10amps into 28 cells.
Anyway, every negative post has corrosion, blue on the copper and rust on the steel! This is sitting on a bench in a climate controlled basement, my electronics lab. The impression I get is the electrolyte is leaking under load from the Neg Post seals. I am going to try the nickel buss plates available and hope it is more resistant to the electrolyte.

Since my basement is not subject to wild humidity changes, moisture is not the only problem. That said, humidity and condensation is a factor likely making the electrolyte leak worse by making it spread on the bars. I cannot see any other explanation for the corrosion that occurs in the orange sense connector in the Batt ECU and it happens to be the only non-gold connector on the ECU.

 

Pic