here is an update. i'm still at the point where i started with nitrates. i removed all my bioballs, but few that were covered in sponge. i feel bad killing the sponge things, so it's about 10 bioballs that still in the filter completely overtaken by sponges. now, i got nitrate removing filter that i attached to my ro/di system, but the nitrates still not complitely out but at .5 ppm. before i got nitrate removing filter the nitrates read 10 ppm before and after ro/di proccess. i'm going to try new bag of live send to recharge my send bed. i'll wait another week and see if the nitrates will go down without bioballs and recharged send bed
