How much variance in alkalinity per day is acceptable?

[housemouse]

What is the maximum change in alkalinity per day to be considered "stable?"

I use dosing pumps to try to stablise it, but people are reporting single figures, and I get a range. Is it the carbon dosing? My tank has also been mini-cycling arising from deaths, and also, I'm vinegar dosing. Are those factors?

Thank you sir.

 

[vic5hands]

Depends upon what you are keeping in the tank
Reef or Fish only [emoji228]

 

[housemouse]

ULNS SPS-dominated

 

[Randy Holmes-Farley Verified Community Expert]

It also depends on what you mean by stability. hour to hour/ Day to day/ week to week

For the most particular corals, I don't think that anyone believe that a variation of less than 0.15 dKH is needed over any time frame.

Most peopel think 0.25 dKH range generally is OK.

Many will say +/- 0.2 dKH for a range of 0.4 dKH is fine.

I think it is somewhat of an open question whether the variability over a 24 h period is a concern if it is the same day after day. I think many people with high end tanks often have +/- up to 1 dKH per day, but then back to the same point the next day.

 

[housemouse]

More or less something like this:

Is my current state. I'm trying to go for ULNS and something close to NSW. My last measurement was 7.5 dKH, just now, after the vinegar overdose.

 

[Randy Holmes-Farley Verified Community Expert]

Any alk depletion from a vinegar overdose will come back as soon as the vinegar is metabolized.

 

[emvanburen]

This swing is becoming an issue with me given coral growth - curious if the thinking has evolved much on this since the last post in 2018?