From what I understand, you are planning to connect multiple grow sites to a master res, using a brain bucket to control water level. This means all the grow sites share the same res.
If it is a situation where, every two weeks you take a plant from the veg room to the bud room, my concern would be that you are moving a new plant to essentially the same res as old plants. Plants that are near finish will demand a high ppm that the new ones are not likely to tolerate. You would also not be able to do a final flush that way, since only a fraction of the plants in your res would be ready for it at any given time. You would pretty much be limited to filling all the grow sites up at the same time, so that all the plants are on the same feeding schedule, and all the plants would need to be the same strain, or strains that feed very similar. I'm not saying you shouldn't do it, just that you should be aware of the limitations. You would be building an elaborate system with more parts to get clogged and need cleaned which has inherit limitations the simpler design doesn't have. But again, im not you and I don't know your situation.