Whats the best Ca, dKH and Mg for sps?

[pomme]

Whats the best Ca, dKH and Mg for sps?

I have always heard and been told that you should keep your levels in this range:

Ca - 380 - 460ppm
dKH - 8 - 12
Mg - 1250 - 1600ppm

now these are a big difference between the two sides of the scale.

I was told that you should keep your dKH high as this will keep the pH change from day to night as minimal as possible. So with doing this you are also keeping your Ca and Mg in the upper scale (if using a ca reactor like me).

But i have heard of people 'burning' there acro colonies from having a stable high dKH.

But i know that we all want to acheive the Nsw levels as much as possible, which is:

Ca - 420
dKH - 8
Mg - 1400


But i was wondering what was best, whether to have a lower dKh (eg 8)and risk the pH fluctuation, or have a higher dKH (eg 12) and risk acro 'burning'?

Whats your thoughts?

Andrew

[nhlblues44]

Andrew,
I have heard that high alkalinity is good for the sps's coloration. I just started keeping sps's myself a couple months ago. The alkalinity is sky high in my sps system(not by choice just ended up that way after years as a fish only tank using ph buffer too much i guess. My ph is 8.3 solid day or night as my alkalinity is 16dk believe it or not. Even with the alk. so high i have no burning of the sps's and they all have great color and are plating and growing good. I'm trying to get the alk. down to 12 or 13 though in the long run. I also have a orange cap frag in my soft coral tank where the alk. is only 8dk and he is doing great also, so this may be a little confusing but as you can see success can be attained at both ends. I don't know much about sps's yet so take what i've said and consider it ONLY MY personal experience. Jim

[pomme]

yeah i have leveled mine out at 10 dkh just for being in the middle, and everything seems to be doing well, and more colour coming out but i think this is from the lights i added.

[Spanky]

You can get alk burn from too high too long.

I stay in the 400 range on Ca and the 8-9 dkh. If you're having pH problems, look to better circulation and less CO2.