So after my most recent massive water change, I took a nitrate reading with my API test kit:
The test kit read 80ppm, and I also tried measuring a sample of half tank water and half extra saltwater that I had pre-mixed. The test kit read between 40ppm and 80ppm on that. Would I be correct if I said that diluting the sample like this will not give me accurate results with my API test kit, since it could be measuring things that are in my non-tank-water?
If I understand this correctly, that means my nitrates are somewhere around 20ppm. This would line up with the fact that the fish that seem sick/stressed are looking much better. I really hope it was just the nitrates that were giving them problems.
I think what I want to do over the next week is:
no water changes. I want to do another reading a week after my last reading and see exactly how many nitrates my tank is generating as is.
I think I want to remove the chaeto from my refugium. I feel like it isn't doing any good, and it's hideous to look at.
I think I want a biopellet reactor. The set-and-forget self-regulating nature of this is worth the extra money to me. I have a couple of questions about this, though. Most of the units don't appear to have a pump included. I'd kind of like for this to be in-sump instead of pumped externally. Is that possible? I'm not sure quite how to accomplish that, and what kind of setup I'd need (or what kind of plugs to get on my biopellet reactor) for that. Any suggestions?