DkH

[Aquattro]

With my 150, my SPS grew so fast that I couldn't give away frags. My Ca was about 400ppm, and alk was anywhere from 8 to 11. Mg never got tested.
I used a large Ca reactor, which I suspect helped a lot, and 2x400w Radiums.
In my current tank, values are mostly the same, although I fight with my reactor (hence, and with alk) and Mg is ~1400ppm. It's been running almost a year and I have hardly any growth.
I doubt I've had enough growth in this year to match what I used to get in a month. So personally, no idea what makes them grow like weeds.

I do have colors like I never had before, so it's a decent trade off.