I have found what might be the reason for my problems, but I don't know what the cause is. I did water tests yesterday. I'll admit I have been lax in testing but my water quality has usually been good, until now. My nitrates are testing above 20 for the fist time since having a SW tank. Up until now I never had more than a 5 ppm reading. Funny thing is, I would think adding a sump and doing all these things would improve the tank, but it had got worse.
So today, I did a 10g water change but the nitrate reading has not budged, and actually looks worse. I am mixing another 10g tonight to do another change tomorrow. I'm using DI water with no nitrate reading, so it's not coming from the water source. I suspect it is coming from the feedings. I was feeding every day and feeding flake. Only as much as they would eat in a few minutes and a veggie strip for my tang.
I fear the digi is all but dead. I took a good look at it tonight but could see no polyps. I moved it to a position that is easier to see in the tank. I will check it again tomorrow. The xenia has just been hanging on, barely. I'm really worried about my new additions, although the Kenya Tree looked really good today I worry that it will deteriorate if I don't fix the water parameters.