Is there a point where you can have too much bio media and some of it is useless. I have added matrix bio media to my emperors and each time I added more I noticed less buildup on my biowheels.
if you have one two inch fish in a large tank yes but if you have a heavy bio load no good bacteria can only survive if it has a food source and o2. so really it depends on the food source.
You can't have too much biomedia, you can't have too much bacteria, they only thing you can have is too much waste, but then just get a bigger tank with more biomedia and you will be fine.
There will always be a point where you could have too much bio media and some will go to waste. You have to find a good balance of filteration stock etc. Like I said before it needs a food source to live, fish waste being the major part etc. Usually this is not the case mor bio media the better but there are instances where people over filter and under stock and may not need all that area to cultivate the good bacteria.