So, here's a water chemisty n00b questions:

I have only been keeping SPS since November, and recently been increasing my SPS frag collection (I now have like a dozen SPS frags and two clams, most frags are pretty small). I don't see big swing in my Calcium. In fact, it's been at ~500 for over a week and I have not dosed (I did do a WC last week, and again this week). dK has been fluctuating a little, I add a little B-Ionic #1 daily to raise it from 9 to ~10. Mag is at 1500-1600 (I'm keeping it higher to deal with the last of the briopsis/gha). Am I doing something wrong potentially, or are my SPS frags not big enough to be making a noticible dent to my Calcium?

BTW, I use Tropic Marin Reef Pro salt...

imo alk always affects calc, normally lowering calc as alk is added

Weekly water changes balance this out, and if your saltblend is at 500ppm after you mix it then you may not see a huge drop in calc because of this

i only use Elo's test kits as i've found many others to no be accurate, basically they'd read the same level everytime i tested no matter where my acually Calc level was at so you might look into getting a back-up test kit

if your tank is only lightly stocked you may not notice any increase in calc and alk usage until those corals actually get used to your system and then start growing

but IMO you aren't doing anything wrong, just keep an eye on your corals and possibly get another test kit to confirm what your kit now says your calc is at

Exactly! That's what I'm afraid of - I keep dosing Alk, but calc is not be affected! WTF! Well, I think getting a backup test is certainly a good suggestion. I use Saliferts tests - I'll check out Elos, a lot of forum peeps are using Elos brand tests. Maybe even take some of my water to the LFS to test Never done that before, maybe that's a good thing

you will dose a lot of alk for every bit of calcium you end up using.
i think about 2-3 dkh corresponds with maybe 10ppm of calcium use

Salifert should be very reliable, at least as much as Elos. In the meantime read this:
http://reefkeeping.com/issues/2004-12/rhf/index.php

Excellent article! It really helped to clarify things and confuse the schit outta me at the same time!

"If an aquarist is supplying a balanced additive to his aquarium, and calcium seems stable but alkalinity is declining, it may very well be that what is needed is more of the balanced additive, not just alkalinity. "

So I should dose equal amounts of B-Ionic 1 and 2, even if my Ca level is good?



Edit: that would make sense, since if dhK fluctuates so much more than Ca, then why else would B-Ionic come in two equally sized bottles?

balanced additive? isnt that like kalkwasser and CA reactors?

Alkalinity addition will only affect calcium concentrations when one or both are already at the supersaturation limits in seawater. Adding the supplement too fast or overdosing will cause this. Otherwise, one should not really measurably lower the other. If it does, you are getting precipitation out of it, even if you can't immediately see it.

Also keep in mind that calcium is depleted at a much slower rate since there is a very large sink of it in seawater. In terms of calcification, takes a decrease in 2.8 dKH to get a loss of 20 ppm of calcium. This is also what is referred to as balanced depletion. You should imitate this ratio when adding supplements for maintenance (unless one level is substantially lower than the other, in which case it is fine to balance them manually). Most "balanced" supplements already follow this particular ratio--2 part solutions, calcium reactors, kalkwasser, calcium gluconate additives all add equivalent amounts according to this ratio.

Sound like you are doing right as far as I'm converned, that is what my levels stay at. Do you notice excessive buildup on your pumps? If so what you are adding is precipitating, and you shouldn't really notice a swing at all with only frags order some colonies or a clam and then you will have work to do. Coraline is a major user of calc as well, I need to post an updated tank shot so you can see what I mean. I have had an explosion of coraline since the addition of my 20k halide.

wow, thanks amph, i was about to ask that question

i thought that the whole 1 meq/l which equals 17.9 or something ppm calcium carbonate equivilant meant that part of it was calcium, and part of it was the carbonate so some kind of split which is why i said about 10 in my post

Thanks, guys. I have not seen any obvious signs of precipitation yet. I will continue to monitor, but otherwise, I'm not getting any big swings in any of my params (well, maybe temp, I think I'm going to start running my chiller again since it's getting warmer now), so I will take it as a "things are going OK" sign.