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View Full Version : Why would Ca drop?



conjuay
04-16-2009, 12:40 AM
The toadstool leathers just refused to open up and stayed that way for two weeks. So I started to investigate.
I do regular water changes (10%) every week, -at very worst every other week. (100 gallon display, 20 more between sump and fuge) Evaporation is replaced with kalkwasser, usually five gallons a week. The tank is almost ALL soft corals, toadstools, leathers, shrooms, a few LPS one monti and one acro...

So why did my calcium drop to 270?

I know sps tanks draw alot of calcium, as do clams, etc. But softies are supposed to be less demanding of Ca, and there are no clams around!
Is the Ca being driven down by the alkilinity of the lime-water? My Alk is high,- top of the Salifert chart- 1600 or so...
I should add that Mg is holding around 1250...
Any thoughts?

MegaBite
04-16-2009, 07:39 AM
Check your CA kit with another one or at the LFS before you do anything else to make sure it's accurate. I also top off with Kalk (about 3 gallon per day evap) and have lots of SPS and a couple of clams and my CA stays at 420 - 430.

Beamers
04-16-2009, 11:24 AM
Out of curiosity how much kalk do you guys add to your top off water? I always thought I was adding too much because my calc was always very high (500+) so i've been weening it back lately.

Since then i've noticed my ph is dropping more then I would like .. but my calc is at a decent level.

I lose about 2 gallons per day and just add 5 gallons of RO every few days. I don't dose the top off water with kalk every time to avoid it shooting too high. Maybe i'm not adding enough Kh/Alk to counteract ?

conjuay
04-16-2009, 11:55 AM
Out of curiosity how much kalk do you guys add to your top off water?
I lose about 2 gallons per day and just add 5 gallons of RO every few days. I don't dose the top off water with kalk every time to avoid it shooting too high. Maybe i'm not adding enough Kh/Alk to counteract ?

I don't add kalk everytime, I believe the stuff that precipitates out of the first batch provides enough hardness for several buckets worth. (That might be my problem.) :roll:

But Beamers, how do you 'buffer' the new water w/o kalk? straight RO water is rather 'soft'.

conjuay
04-16-2009, 12:00 PM
Check your CA kit with another one or at the LFS before you do anything else to make sure it's accurate. I also top off with Kalk (about 3 gallon per day evap) and have lots of SPS and a couple of clams and my CA stays at 420 - 430.

I will check out the kit, but the corals have seemed to confirm the Ca was low.

Beamers
04-16-2009, 12:10 PM
I still buffer my top off water every couple buckets worth. Although it seems like when i manage to get my PH where I want it, my calc ends up being too high from the kalkwasser.

Maybe i'm just not drip dosing my kalk slow enough? I found a neat read on kalkwasser and how it reacts with the water. Might also explain why your ca is dropping while other water parameters are fine.

http://www.reefscapes.net/articles/breefcase/kalkwasser.html

MegaBite
04-16-2009, 01:15 PM
I'm not sure if I'm doing it right or not but all my parameters are always spot on. I add 2 tea spoons (10ml) of kalk powder per gallon of R/O water dumped in to a 40 breeder that I use as my top off tank.

It's hooked into a JBJ ATO and I use an Aqualifter to pump the water. I like the Aqualifter for this because the most it can pump is about 3 gallons per hour incase something gets stuck and the JBJ also shuts down if it pumps continuously for a few minutes. Nice safety feature.

YodaHart
04-16-2009, 02:47 PM
Have you tested your water-change water, too? If you do a lot of water changes and that water has low calcium then your tank will, too.

skinnyjoe
04-16-2009, 08:31 PM
hey you really need to check your alk. bet you it's through the roof if you find that calcium kit is good. don't add anything else for at least 2 weeks and do a bigger water change. try 40% just make sure your temp, sal, and ph are the same for new water and old water. that should get it back in check. i really don't check cal to much, imo alk is more important and it will almost always tell you the calium number by it's results. if my alk is running 10dkh then my cal is around 400 and that's about perfect for me.

conjuay
04-20-2009, 11:45 AM
hey you really need to check your alk. bet you it's through the roof if you find that calcium kit is good. don't add anything else for at least 2 weeks and do a bigger water change. try 40% just make sure your temp, sal, and ph are the same for new water and old water. that should get it back in check. i really don't check cal to much, imo alk is more important and it will almost always tell you the calium number by it's results. if my alk is running 10dkh then my cal is around 400 and that's about perfect for me.
Yes, my alk is high...
I guess I'm running kalkwasser too frequently :(

Thanks, I bet that's it.