CA/ALK/PH and MG questions
 

Hi all,

I have been using the home-made 2 part CA and ALK system for a while now and have noticed lately that my ALK always drops faster than my CA!

In the span of a month, my CA went from 400 to 380 while my ALK went from 9.2 to 6.4.

I haven't started adding the third part to the equation and that is the magnesium sulfate.

I have already added the ALK once by itself without adding any CA hoping that would fix it, but it didn't.

The questions that I have are:
1- Is the CA drop normal for an average stocked sps/clams tank in 1 month?
2- Is the ALK drop normal for that tank in 1 month?
3- Is not adding the magnesium sulfate the reason for the ALK swing?
4- What can I do to balance out the equation and where am I going wrong?
5- How bad is ALK 6.4 to my corals? Do I need to panic?

I have a 72gal tank with low bio-load, 100+lbs of lr, 4" aragonite dsp, and a good skimmer.

I have a few good sized sps colonies, 2 large clams, a couple of large lps, and numerous frags of sps.

Thanks for taking the time to read, and I appreciate all the help I can get.

Fresh.

What's your Mg level ?
I'm surprised that your Alk drops so much with DSB.
Ca drop is somewhat large, hard to say.
The third part should actually be mag sulfate and mag chloride (2:3).
Alk swing like that are bad, you should dose more frequently (daily).
Alk 6.4 not a panic, but immediate action necessary.
My guess is that you Mg is low (~1000).
Aim for more stability, possibly invest in a dosing pump.
Hope this helps.

Your ca dropped from 400 to 380 in a month with sps colonies and clams?
What are you measuring with?

salifert test kits. I was told those are the best in the market!!!

So Denis, you are recommending that the swing is due to the magnesium sulfate, is that correct?

not sulfate, just magnesium,
Do you have a testkit for Mg ?
I also use Salifert.

Well, according to the 2 part home made additive, the 3rd part to balnce out the magnesium in the system is epsom salts and that is magnesium sulphate!!!

Yes, that's the old method that leads to buildup of sulfate.
Look at this new one : http://reefkeeping.com/issues/2006-02/rhf/index.php

I'm still looking for that MgCl , food grade is too expensive (5kg @ $95.40).
Any one knows where to get Mag Flakes (by DOW) ?

http://www.canreef.com/vbulletin/showthread.php?t=25122