Feeding heavy to increase nutrients, now Alk is dropping faster and Ca is elevating...

Z Burn's Reefing

Active Member
View Badges
Joined
Jan 29, 2016
Messages
222
Reaction score
267
Location
Utah
Rating - 0%
0   0   0
Hi All, 2 weeks ago my nitrates and phosphates were both bottomed out and near zero. As a result, I started feeding heavier and more frequently. Over the last 7-10 days I now notice I need to dose more Alk than Ca to keep my levels in range - which oddly enough has given me an even greater pH boost, lol. (I target alk of 8 and CA of 450)

Can feeding heavy to increase nitrate/phosphate cause Alk to drop and not Ca? Since its dropping more than my Ca, I am assuming the drop is not due to coral growth/calcification, but something else going on. The only thing I've changed is feeding heavy. As a result of this, I have to dose more Alk than Ca to keep Alk in range...if I dose equal parts of Alk and Ca, then my CA starts to get too high (nearing 500, when normally I keep it close to 450).

A few questions:
1.) Is this observation real and can be explained scientifically? Or have others experienced this? Or perhaps the concentration of my 2 part is messed up...
2.) If I continue to feed heavy, will Alk consumption continue to be greater than Ca consumption? Or does it eventually slow back down?
3.) During this period of heavy feeding to boost nutrients, am I okay to dose more Alk than Ca to keep my numbers in range? I use B-Ionic 2-part. I have always been advised to always dose in equal amounts, so curious if there will be issues if I don't dose in equal amounts while driving nutrients up...

Thanks for any insights!
 
Last edited:

Randy Holmes-Farley

Reef Chemist
View Badges
Joined
Sep 5, 2014
Messages
67,438
Reaction score
63,839
Location
Arlington, Massachusetts, United States
Rating - 0%
0   0   0
Feeding more does not directly impact alkalinity.

I expect that the result, if not just testing or dosing variability, is due to corals calcifying faster, which is far more readily detected by alk decline than the very slow calcium decline.
 

Randy Holmes-Farley

Reef Chemist
View Badges
Joined
Sep 5, 2014
Messages
67,438
Reaction score
63,839
Location
Arlington, Massachusetts, United States
Rating - 0%
0   0   0
Just chiming in to say none of my tanks consume alk and calcium equally.

There are clear reasons when and why they do not.

Folks should not think it is a random thing. Corals and coralline algae always use a fixed ratio, but things like water changes, accumulating, declining or dosing of nitrate, and sulfur denitrators can all mess with the apparent ratio.
 

Bubbles, bubbles, and more bubbles: Do you keep bubble-like corals in your reef?

  • I currently have bubble-like corals in my reef.

    Votes: 16 34.8%
  • I don’t currently have bubble-like corals in my reef, but I have in the past.

    Votes: 6 13.0%
  • I don’t currently have bubble-like corals in my reef, but I plan to in the future.

    Votes: 15 32.6%
  • I don’t currently have bubble-like corals in my reef and have no plans to in the future.

    Votes: 8 17.4%
  • Other.

    Votes: 1 2.2%
Back
Top