So each day on every forum on the web there are questions about bacteria and what they require, don't require, tolerate and will not tolerate. And 99% of the answers are unmeasured, they're recirculated info for decades regarding marine cycle/filtration aerobes and they're not measured using...
www.reef2reef.com
you are about to set up a system that belongs in the untested portion of that thread, very rare to find new material our hobby has 0 reference threads for. even though we all predict your linked systems will cycle, nobody's measured it. its been total guesses for a long time
you will be 99% of the way able to make inference on what bac do/if they transmit if you will unlink your systems just before the final move over, and lightly test/prove the new system can handle ammonia. try to see if 1/2 or 1 ppm of ammonia can be cleared over nite by the new system. **if using api ammonia, look for any movement down overnite it doesnt have to be total zero for obvious api reasons heh
you dont need a huge amount or even 2 ppm, literally any ammonia command proves bacteria are in the water and of significant levels to actually cycle another system within the 30~ day timeframe by sheer linkage
your experiment will address these false assumptions (if it works, if it doesnt they're true assumptions lol):
-when extra surface area is provided, only more feed can allow a bacterial biomass increase to take over the new system. Your system will not be getting new feed or new + bioloading, only the current amnts handled by the current system remain. The new surface area will be taken over by biomass that was already accustomed to X amount of daily waste, and thats amazing resourcing if it does occur. it could indicate that bac receive nutrition from sources other than human masters (how did they ever survive before we were on scene with liquid ammonium chloride to permit them lol)
-that insignificant amounts of bac are in water. **aquabiomic's studies have measured bac in water, but now we want to see practical measures. Can you bring up a giant +100 gallon system with orders of dry surface area with water-only transmission> if not, reef water only has sparse nitrifiers riding rafts in suspension, if so it means there are significant amounts. **some very very high level reef biologists have said firmly there is hardly any nitrifiers suspended in water** your test can put a final stamp on that statement