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View Full Version : Calcium high, pH low, alk ok


whalloper
05/29/2006, 04:41 PM
another day, another problem...

my top-off system decided to go nuts and dump all of the water (thankfully only about 4 gals) into my sump. My top-off water contains Seachem Reef Complete (with magnesium and strontium).

Needless to say, my calcium is above 500ppm. My pH has dropped to 7.8 (yikes) but my alk is ok at 9dkh (typical). Salinity is lower than normal from all the fresh water, but not much. So, does this make sense? I would have thought my alk would have dropped to cause the pH drop - am I wrong?

So to sum up params:

Calcium 500ppm+
Alk 9dkh
pH 7.8
Salinity 1.025
Nitrates 0
Phosphates 0

I dont test magnesium and strontium, could excess of these lower pH???

whalloper
05/29/2006, 04:43 PM
oh yeah, is there anything I can do

RobinsonFam1
05/29/2006, 05:54 PM
lots of times ph drops when ca goes high all at once like that. you can use all sorts of methods to raise ph and lower Ca. easiest is to do a water change with correct parameters. depending on you load the Ca may come down quickly.

jer77
05/29/2006, 06:35 PM
Heres what is said in this article about your problem:
"If alkalinity were less than 4 meq/L (11 dKH; the most common situation in zone 4; shown in Figure 5), I would advise correcting this problem by adding an alkalinity supplement until you have moved into the target zone (or zone 1). For systems with a pH of 8.2 or above, baking soda (sodium bicarbonate) is a good choice. For systems with a pH below 8.2, washing soda (sodium carbonate) is a good choice (though use some baking soda too if the correction is a large one and the pH gets too high; that is, above pH 8.5 or so)."

here's the link:
http://www.advancedaquarist.com/issues/nov2002/chem.htm

jer77
05/29/2006, 06:37 PM
I would however do a water change like suggested if the cal levels are above 500 ppm.

RobinsonFam1
05/29/2006, 06:51 PM
jer77: please inform me as to why no water change. im not arguing but rather looking to learn..

thanks!

scottief
05/29/2006, 07:04 PM
Hi all, I had the same problem low ph calcium OK alkalinity OK. I read the above link provided by jer77 and read that running a natural gas or lpg gas heater during winter absorbs available oxygen and increases carbon dioxide. I adjusted my ph levels to normal and now leave windows and doors open during the day as much as possible. I do realize that in some parts of America this is not possible due to the extremely cold winters you have there.

whalloper
05/29/2006, 07:17 PM
thanks jer77, those graphs are very helpful!! Its been a rollercoaster since going SPS