Duncan Head Not Happy

[Scrubber_steve]

Could Potassium or strontium have anything to do with it. The ICP came back and K is at 311ppm and Sr is at 6.3ppm.

The photo below is of a Duncan I had a few years back.
The polyps grew to about 3" in diameter, new branches popped out, so I cut off a section & had two Duncan's.
It was going marvellous.
I discovered the water parameters at this time were -
NO3 - 60 ppm +
PO4 - 3.0 ppm (yes, you read that correctly)
Alk - 16.8 dKH (300ppm)
CAL - 550ppm

When I corrected the water parameters to align with the usual recommendations the Duncan's slowly died, & I have never to this day been able to keep a Duncan. :(

I know this is anecdotal & doesn't help you, sorry.