Isn't Marshall Islands really hard to get now? Tonga is hitting $10/lb at the LFS
's that have it here (2 that I have seen in the last 45 days).
Ive already cherry picked the tonga from them for my bigger tank. Maybe I should just go and get some cheapo live rock and smash it with a hammer then epoxy it back together in weird shapes.. nobody would notice!
As for the 2 tanks plumbed together, I was thinking about that issue too. I'd rather have as much biological filtration as possible, but I can run 2 individual tanks if needed.