[Canadian]

Thanks for the replies.

I'm still leaning toward the lack of coralline in my case being the result of high nutrients that aren't being picked up on testing. As I mentioned earlier, when I blast my rock I stir up the detritus and it gets caught in some of the hair algae on the LR which I think is what feeds it, but there could be some unmeasured nutrients in the tank that are also contributing to it. I also think this is why briefly adding sand lead to a brief explosion of coralline - the sand acted as a nutrient sink while it was in there briefly.

My Ca is quite high as well Brad (often testing at 500+) and I do notice I get more encrusting than vertical growth. I might try to change my dosing on my dosing pumps to see if I can bring it down a bit and see if it has any effect.