Hey there,
I had/have this exact issue with my tank and it is 5ish months old. Sent in an ICP test and found it is contaminated with heavy metals, the worst of which being copper, all from an unknown source. I also started my tank with 100% dry rock and sand and I suspect the source is the rock or sand.
I would send in an ICP to see what you may really have going on in your water. I use ATI because they test for the broadest spectrum of parameter and contaminants, and they also test your RODI water.
My journey with my nightmare tank can be found here:
About to Quit
TLDR (07/04/21): After a full spectrum of troubleshooting, I sent in an ATI ICP test. Results can be found in post #366, but the short story is I have heavy metal contamination (copper, aluminum, tin, zinc, and manganese if I remember correctly) in my water stemming from an unknown source. I...www.reef2reef.com
I sincerely hope you don’t end up with the same issues I have and hopefully your tank gets up and moving soon.
Best of luck!
I’d recommend doing an ICP test.
what’s your water source?
Currently awaiting the results of an ICP Test from TRITON. Sent the package a couple days ago so it should be ready soon. Not sure how long it takes but I've read maybe a week?