Running Kalkwasser more at night beneficial?

[Koigula]

I have a 151 gallon tank with 60 gallon sump and 20 gallon refugium running 3+ liters of Kalk solution a day. I currently run evenly, day and night with OSC prgram from Neptune through Avast stirrer. Kalk saturation levels are steady 80% +/-5 and alkalinity run steady by (almost) daily eveing testing at the same time.

I read banter back and forth if running kalk more at night might be beneficial, say 2/3rd of current dose added at night to stabilize the diurnal pH swings.

Is there a consensus on this or does it not matter much?

pH is 8.05 low to high of 8.2 currently. Alkalinity is 145ppm as CaCO3 +/- 5 ppm drifting upand down as demand is met with increases.

 

[ScottB]

I am still tinkering with mine, but yeah, I dose heavier in the evening via APEX DOS. The DOS makes it so easy to fine tune. I am keeping a pretty good range these days. Best thing about it is it cut my 2-Part dosing in half. Before, it was 1/2 liter a day which is a lot of mixing/refilling.

I guess I read a Queen City Corals article about night time calcification rates rapidly increasing with higher pH. I have no personal objective measure, but it "feels" better.

 

[Koigula]

Your swing of 0.15 pH units and low of 8.25 look good. I was not terribly convinced by that article so was looking for other opinions. I found more of a correlation by upping T5 intensity and see alk demand increase.

I much prefer using balanced additives as all paramters seem a bit more stable. I never adjust much with this set up and 15% weekly water changes.

I do easily find adding more kalk adjusts pH more than it raises alkalinity with little wild alk swings. It is hard to over adjust with Kalk to increase alkalinity. I read 3.5l of kalk equalos roughly 80cc of each component.

 

[ScottB]

I do easily find adding more kalk adjusts pH more than it raises alkalinity with little wild alk swings. It is hard to over adjust with Kalk to increase alkalinity. I read 3.5l of kalk equalos roughly 80cc of each component.

I did a very slow & cautious dial up on the kalk volume.
Just like you, kalk is only about managing pH. Once I solved for that, I adjusted my 2-Part to solve for dkh.

I haven't adjusted the kalk volume in months now.

 

[Koigula]

I may just dial it up for 0.1 pH gain like yours. Pump runs 2 min every 58 mins already. I think over 8.15 at night is all that is needed. ACI had a video on ReefBum Youtube channel about this topic too.

I live near Queen City Corals but never went. I should go sometime. I just have enough SPS to grow out and no health or pest issues.

I am adding all for reef powder to continue balanced additives further. I have a LifeReef Calcium reactor I rather not use and do not need currently or likely in 2022