Hey gal...
me no expert, but i tink the lack of sandbed is not allowing enough area for the bacterial to grow... you'll be surprised with the effect of having more sand in your reef tank... bear in mind that in the ocean, there is sand everywhere....
I have been battling no3 for months and it always hover around 40ppm, in the end i took out my bioballs and it dropped to almost 0ppm.... dat coincided with the fact that i stopped my feeding for 2 days... so i dunno which is the main course... u may wanna try to remove your bioballs if u have any...
Also, if there are any fatalities, make sure that it's removed, as they contribute to ammonia and so on...
During feeding time, try to switch off your pumps, so dat food has less chance of being blown into crevices where u fish cant reach, they might decompose there for a while until the hermit crab or shrimp come along to eat it... den switch on your pumps again so dat the uneaten food dat has settled on your sandbed will raise up again, giving the fishes another chance to eat them...
my 2 cts worth...
Vincent Ho
PS : sorry, haven't got time to call you regarding the DW... maybe next week k? this week too busy liao! Happy Valentines!