Well if the nano is devoid of livestock you can pull all the bioballs out at once. Otherwise it is best to remove like 20% every week until they are gone.
I missed the question above on LS being better in the main tank or sump. The question here is how big is the sump? You want as much surface area for the DSB as possible and a small sump, in the 20-30 gallon range, doesn't have that much of a footprint. There I'd use the bed in the display. With bigger sumps you can give it a shot using the sump. If denitrification is not occurring in a few weeks after starting the bed then you can always add one to the display.
I missed the question above on LS being better in the main tank or sump. The question here is how big is the sump? You want as much surface area for the DSB as possible and a small sump, in the 20-30 gallon range, doesn't have that much of a footprint. There I'd use the bed in the display. With bigger sumps you can give it a shot using the sump. If denitrification is not occurring in a few weeks after starting the bed then you can always add one to the display.
