Duncans and nitrates

[pseudorand]

Has anyone else noticed that Duncans don't do well with high (or possibly just changing) nitrates?

I went on vacation and mi nitrates spiked because I feed dry instead of frozen. Everything appears to have survived, but my two duncans are open much less today (my first day back). I seem to have a vague memory that the same thing happened when a did a test run of dry food a few months ago. Is that a well known thing, or just my imagination?

 

[T-J]

What do you consider high?

I keep my nitrates around 4, and my Duncan’s keep growing new heads.

 

[pseudorand]

They usually hover at 5ppm with two cubes frozen / day in a 120. They spiked to between 20-50ppm (that's the range in my red sea test kit) after 5 days on dry food (combo hakari and brs pellets, smallest setting on my cheapo vacation feeder).

As one might surmise from those levels and that delta, I don't keep SPS, except for an indestructible Idaho Grape Monti. I also have a cyphastia and scroll corals, both of which seem fine (not sure which ?ps those fall into).

 

[CanuckReefer]

My nitrates were at basically zero for years and my Duncan still grew quite well, I'm now up around 5ppm consistently and still producing heads, however I am curious/ might be concerned if it crept up above that, what might happen....