Alkalinity Consumption Help

[Aaron Atkinson]

Hello. I've been really struggling with making sense of my alkalinity consumption. A little bit on the system. It's a 50 gallon display with a 29 gallon sump.

• 60 gallons total water volume
• combined carbon/GFO reactor
• top off water has 5 tsp kalkwasser per 5 gallons of water
• About 40 lbs of live rock and about a box and a half of those ceramic bio sphere balls in the sump
• Nitrate is always zero
• Phosphates basically zero on the meter
• Magnesium runs about 1380 ppm
• pH hovers between 7.9 - 8.1 using a CO2 scrubber on the skimmer air intake line
• I have 8 small corals and five (5) fish

I am currently running just at 7 dKH and adding roughly 3.25 dKH (140 mL BRS recipe) per day to maintain a stable alkalinity. It doesn't make any sense. I suppose I have calcification going on because my pumps freeze every 2-3 months. My idea is to just stop dosing for about a week and let things get coated with whatever...

So I took same data on consumption at various starting alkalinity. I confirmed that consumption drops as alkalinity increases. Here is the chart. Any thoughts would be appreciated.

 

[Randy Holmes-Farley]

Your chart seems to show that demand rises as alkalinity rises, and that is what is expected.

 

[Aaron Atkinson]

So as far as my situation goes, how do I stop the need to dose way more than this trend to maintain alkalinity?