Not having a 1-to-1 Alkalinity/Calcium consumption truly suggest a problem?

[Edgecrusher28]

As the title suggest, should all tanks consume alkalinity and calcium at the same rate if things are running optimally? I mean in theory it seems that when a coral use Calcium carbonate to build its skeleton, the Ions being use from calcium chloride and sodium carbonate would be depleted equally. However, I have never experienced this with my tank; and in fact. To this day, I have a 1.2 DKH consumption per day but only around 20ppm consumption of calcium weekly.

 

[NoohpyT]

Alkalinity is always consumed faster than Calcium in my experience running SPS tanks

 

[Randy Holmes-Farley]

Alkalinity is always consumed faster than Calcium in my experience running SPS tanks

Alk is consumed at about 2.8 dKH per 18-20 ppm calcium when making coral skeletons and coralline algae.

 

[Randy Holmes-Farley]

As the title suggest, should all tanks consume alkalinity and calcium at the same rate if things are running optimally? I mean in theory it seems that when a coral use Calcium carbonate to build its skeleton, the Ions being use from calcium chloride and sodium carbonate would be depleted equally. However, I have never experienced this with my tank; and in fact. To this day, I have a 1.2 DKH consumption per day but only around 20ppm consumption of calcium weekly.

The deviations from the ratio posted above get larger and larger as the daily demand drops. Deviations happen mostly due to issues related to nitrate rising, falling, or being dosed, all of which impact alk.

water changes mess with demand as well, as do certain other supplements, tap water for top off, and sulfur.denitrators.

Dosing pump mismatches and other equipment issues can also confound properly determining the demand ratio.