When I got that red bug it did get to both systems. Of course the cure did as well.

I think outside what youre asking here is the business risk. How much does two systems add to your overhead vice that of the cost should you, worse case possibility, tank your investment in livestock. Your largest investment is in hardware (assuming here) so you'd have to figure out what the bottom line amount and contrast that to your increased cost in maintaining to systems.

I would imagine that if you were really infected you wouldn't be throwing stuff out and the treatment would be wholistic anyway.

Would you be picking your sps and softies from the same source? If so do they separate their livestock? Doesn't do you any good to separate I they don't.

I guess the bottom line for me is that I really enjoy the single system over that when we were running two systems. Too much work and your redundancy isn't redundant anymore unless you pony up that many more bucks.

Ping would be a good guy to ask as he had all seven seas represented in his office, tied to one system.