Yeah, that's what's got me a bit worried. I'm running a roller mat and a skimmer, but have turned both of them down significantly in the last 3 weeks. I had some chaeto growing in a fuge, but removed that entirely at least 2 weeks ago. All of this in parallel with what I think is a drastic increase in feeding.Woah, and it doesn't look like you have many corals. I wonder what is using up the nitrates? Do you run a skimmer/refugium?
This is what my nitrates and phosphates have looked like since I started the tank:
I've read that it is hard to overfeed with frozen foods since 98% of what you are putting in is water. Do you ever use any flake or pellet foods?
I will say that even with two feedings a day using 2 frozen cubes a feeding, the fish don't leave much uneaten. In the tank I have a <4" foxface rabbitfish, <3" tomini tang, 2 <2" clowns, a <1" green spotted puffer, and a 1" yellow watchman goby.