Alkalinity consumption not consistent by day??

brmc1985 · Aug 17, 2021

So my tank is just under a year old and thriving but I am confused as to why my alkalinity spikes are every other day when I am dosing the same daily amount of AFR and supplemental alk. Numbers are attached. Salinity is actually 35 based on calibrated refractometer I’m just too lazy to change it in Apex. PH runs 8.1-8.4 daily. Skimmer with CO2 scrubber turns off at 8.35 so it doesn’t get too high. I have a frag tank(20g) attached to the main system(180g with 40g sump) that runs opposite hours to help with keeping ph more stable. Is there a reason why my alkalinity spikes every other day as opposed to daily? I’m wondering if it has something to do with AFR having to be broken down for alkalinity or the frag tank but I just can’t come up with any solid hypothesis. @Lou Ekus maybe you have some insight?

brmc1985 · Aug 17, 2021

@Randy Holmes-Farley maybe you have a thought?

taricha · Aug 18, 2021

oh that's fun. a 2 day cycle.
That could be hard to track down (something isn't being done daily) there aren't any strong biological rhythms that are every 2 days instead of daily that could cause this.

Randy Holmes-Farley · Aug 18, 2021

What is the timing of the AFR and alk doses? It takes some time for the AFR alk dose to show up on an alk test.

brmc1985 · Aug 18, 2021

Randy Holmes-Farley said:
What is the timing of the AFR and alk doses? It takes some time for the AFR alk dose to show up on an alk test.

The AFR is dosed every hour the same amount and the ALK is dosed multiple times during the lights on cycle. I believe I have found the issue. My doser was set to Day Interval 1 which means it skips a day. Turns out it was user error from not reading the instructions and not some amazing biological phenomenon!

brmc1985 · Aug 18, 2021

taricha said:
oh that's fun. a 2 day cycle.
That could be hard to track down (something isn't being done daily) there aren't any strong biological rhythms that are every 2 days instead of daily that could cause this.

Wow. So while I was checking my doser app(Jebao) I noticed the Day Interval was set to 1 which I assumed means every day. Turns out that means it skips a day after a quick Google search! I have switched the interval to zero so it should be dosing the same amount each hour EVERYDAY now. Im also going to adjust the doses down by 50%

Randy Holmes-Farley · Aug 18, 2021

brmc1985 said:
Wow. So while I was checking my doser app(Jebao) I noticed the Day Interval was set to 1 which I assumed means every day. Turns out that means it skips a day after a quick Google search! I have switched the interval to zero so it should be dosing the same amount each hour EVERYDAY now. Im also going to adjust the doses down by 50%

Makes sense.