I've got a 135g system that is pretty well established after a bit over a year, and I was curious: If I wanted to start up a pico or nano tank, 5-50g, could I run it off the larger tank? As in, rather than constant new saltwater changes in the pico (I've seen people say up to 100% water change every couple days), instead just periodically pulling really well balanced, healthy water from the large tank to replace in small one. It seems like, while the small system cannot sustain the sort of ecosystem that would keep the water stable and healthy, the large tank would necessarily be creating water that was more stable for longer, even if placed in that smaller system. The goal would be: 15g water change every other month (my current routine), but instead of dumping that still-pretty-healthy-water down the drain, use it to replace 15g in the smaller tank (where the water quality deteriorates more quickly). Does this make sense? Any obvious pitfalls? Totally harebrained?