educate me on 2 part buffer ESV B-Ionic

[cheezefrog]

To start out I have a 36g gal system(29g biocube w/ 7 gal sump) using RC w/ 15-20% water changes weekly.

Tank parameters I try to maintain:
Cal - 420ppm
Alk - 7.9-8.0dKH
Mag 1320-1350ppm


I have added quite a few frags and other corals as of the last few months sps, lps, and other softies w/ data logging for almost the last month constantly. My values show that Alk is dropping .5-.7k dKH (from 7.9-7.4dKH every 3 days), Mag drops around 20-30ppm every week or so, and Cal is dropping 20ppm randomly??? Seems like it'll drop probably based on my water changes but it'll be at 420ppm one day, hold stable for days to weeks, then drop to 400ppm another day.

I've used Seachem products for Cal and Alk with Kent Mag for quite a while, but I just switched to ESV B-Ionic products just recently.

What I don't understand about the dosing and buffer process is...so if my Alk is dropping based on a value of .5dKH(3.2mL) every 3 days, I know I need to dose the Part A(Alk) of this, but how exactly do I figure out the correct amount of Part B (Cal) to complement it with since its varying so much? Planning on going with a Jebao doser as well so I'd like to get this finally understood and sorted out.

thanks for any information

[pokerdobe]

Tagged for my own interest. Just started using the same 2 part.

[mitchellc]

First off what type of test kit are you using? I use Red Sea pro test kits, with pretty good results. Remember that test kits do have a slight degree of inaccuracies. Plus or minus 5 to 10 parts per million. Also with your recent acquisition of new corals, your numbers are going to jump around a bit, as the corals adjust to their new environment. If your calcium drops by 20 parts per million after three days, don't dose Ca. Wait another 3 days, and test again. Try to find the trend. Over time it will stabilize. It is ok to only dose Alk. You will figure it out.