Impello got back to me today, nice person and very helpful. Yes every time we change the res we are dumping the culture in there but no we dont need to feed at a higher rate than with soil. That part confuses me. If we feed tibus to soil and hydro at the same rate and we dump the culture we have in hydro each res change why would it need to be replaced in soil? Over thinking again

No turf wars amongst bacteria an doing a 24 hour soak with just root supplements is a good idea according them. The plants in coco and the RDWC seem to like it.
When I change the water in the RDWC dust the root balls with Azos and they seem to like that also. Brix is up and the root balls are huge.