I hope your not serious about the MP40 in a nano I think 20% is the slowest you can get, feed speed is 10% enough water movement to make the food move in the tank and entice the fish to chase them and how many gallon is the nano?
Are you realy serious MP40 in a nano!!!!!
Depending on how deep the scratches are Novus 3, 2 & 1 will be good for fine scratches, but for deep scratch wet sanding with orbital sander from 320 to 2,000 grid if you have not done it i suggest have a professional do it.
Experience, 2010 neglected my tank due to heavy work load bryopsis bloomed and almost covered the whole tank don't want to use Chemical did my research on a natural way to get rid of it and found a fish that will do i, luckily there was a hobbyist who's trying to get rid of the said fish and...
Good Luck on the exam Mike, and no we will not change to that smalltime (Mike) unless the offender is a really an @$$ sorry to say bad word LOL, we have been pretty good on that subject.