Alk, Ca and Mg for LPS. Should I raise? in which order?

[Magik]

Hi,

I have an LPS dominated reef, my parameters are within ranges recommended by Randy's 2003 article, but I noticed that these days most people have e.g. Mg higher.

Randy, are your recommended levels still the same as in the 2003 reef alchemistry article?

My current levels: Alk 7.3, Calcium 412, Mg 1300, salinity 34-35ppt, Temp 78F

I was thinking at least of raising Alk a bit, to 8dKH, so it is not so close to the lower bound. It seems that most people have also Mg around 1400 these days. I wondered if I should target different levels, like Alk 8-9, calcium 400-450, Mg around 1400? or is it only for SPS? If having Alk/Ca/Mg a little higher, in which order I should change them? I have Randy's DYI baked baking soda for raising Alk, separate Ca and Mg additives, and balance Ca/Mg/Strontium additive. All comments will be helpful. Tank is 4 months in the current tank, but LR from my older established tanks.

 

[hkgar]

I have a SPS tank with some LPS in the lower areas. I maintain alk of 7.5 to 7.8, calcium at 450 and Mag 1350-1400

Here is a good thread for reference. It is about SPS but I don't think there requirements are much different.

http://reefcentral.com/forums/showthread.php?t=2253547

 

[Potatohead]

You're not far off. I'd bring alk up to 7.8 or so and mag to 1340, but 1300 is no problem.

 

[bertoni]

The levels are fine as is, but raising the alkalinity might get a bit more growth, and will give you some leeway in case of testing problems. There's no need to raise the other parameters. Calcium at 412 ppm is very good. The canonical ocean average for magnesium is 1270 ppm or so, and that's what I'd target. Higher levels should be safe, though.

 

[Magik]

Ok, thanks everybody, so I will just raise alk to 8 and let everything else be and will retest Ca and Mg next week.

 

[bertoni]

You're welcome. Good luck!

 

[curiouser]

Can magnesium be added to kalk reservoir to dose both (via ATO) at same time from same reservoir? If not, what is easiest way to dose both?
Thanks

 

[bertoni]

No, the magnesium will precipitate as magnesium hydroxide due to the high pH. You will need a separate doser to add magnesium automatically. If you are using a low-pH alkalinity supplement, a bit might dissolve in that, although I'd have to check.