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

[JB NY]

I think you are fine with the alk and ca recommendations. Many, many people keep their alk around 12 dKH. I've never heard of anyone reporting burning of their SPS. Some talk has recently been going on of high alk over time being a contributing factor to RTN, but that is still up for debate.

I wouldn't recommend keeping magnesium higher than 1350-1400 max. I think a good range for mg is 1200-1350.

[Pomme]

my levels at the mo are

ca is 450
dKH is 12.2
mg is 1380

does this sound okay to you?

joe, what levels do you run?

[JB NY]

I think you are fine with those readings. My tank is currently at Ca:470 Alk:10.2 Mg:1320

As I stated before, some people are trying to associate long term high alk with RTN, but I know many people who have run their alk as high as 14 for years with good results keeping SPS.

[Pomme]

cool thanx for the help joe, ill leave as is then :0

thanx

[new2salt2]

how do you convert the dkh from PPM?

[Ninong]

how do you convert the dkh from PPM?

Divide ppm calcium carbonate by 50 to get milliequivalents per liter and then multiply that by 2.8 to get dKH (degrees karbonate hardness -- yeah, it's German!). Example: If your test reads 200 ppm CaCO3, you have 4.0 mEq/L and 11.2 dKH.

[stang69]

Thanks for the conversion's Always drives me nutts trying to convert hehehh



Jeff