filtration question

[new]

i have a question regarding bio-balls and LR. everyone states that #1-#1.5 pg is best for filtration along with a DSB. i have #78 in a 75gl-15gl sump for a 90gl system and do not have a DSB only about 2 inches of LS, could i start to remove the bio-balls slowly and allow the rock to become the primary bacteria home or should i wait until i have more rock? right now bio-load is 1 royal gramma and inverts and polyps.

 

[new]

the rock is in the display and is all cured, i add no more than about 12# of cured rock at a time, most is figi, a bit of bali and a little tonga. eventually want to have a true perc, firefish a jacobs hawkfish(still debating) and a mandarin along with the gramma.