Correlation between low dkh and using high capacity GFO ?

Macropora · Jun 15, 2015

Randy,

I've been using regular GFO for a number of years along with a Calcium Reactor and Magnesium Supplement dosing during the night. I have a 450 gallong system and the dkh stayed steady at 8.5 - 9 dkh during the month. I recently started using high capacity GFO after using up the regular gfo. My dkh is slighly above 7 dkh even with the Calcium Reactor and Magnesium supplement. I'm wondering if the high capacity gfo is too efficient keeping the dkh low. I've noticed this for the past couple of months after the change and have tweaked the effluent in the Calcium Reactor to raise the dkh. Let me know your thoughts. Thank you.

Randy Holmes-Farley · Jun 15, 2015

Using GFO can cause increased precipitation of calcium carbonate on and downstream of the GFO, and reduced phosphate can, in some cases, cause increased calcification by corals.

Both of those effects can cause an apparent reduction in alkalinity.

Macropora · Jun 18, 2015

Randy Holmes-Farley said:
Using GFO can cause increased precipitation of calcium carbonate on and downstream of the GFO, and reduced phosphate can, in some cases, cause increased calcification by corals.

Both of those effects can cause an apparent reduction in alkalinity.

As I suspected... Thank you for the clarification Randy!