Alkalinity fluctuating?

[stebbins]

I’ve been growing sps for a long time and recently added an Alkatronic and trident on to my sps frag tank 60gal. I’ve been looking at my readings/ graphs and what I don’t understand is why my alk usage varies so much. When I test manual (Hanna, salifret) it matches or within less than .2 of the Alkatronic (trident not giving trustworthy numbers still working on that). I dose with brs 2 part and kalkwaser (tank in basement and use kalk to keep Ph up. Kalk is on a versa dosing pump at 1.8 ml per minute up to 2500 ml per day and it’s controlled by my ph probe readings to high shut off. Dos does 28ml per day dosing something like 75 times per day. The one dip on graph was when kalk ran out. Ph low is around 8 ph high is just below 8.4.

I’m curious if other people have this much swing in Alk or if it’s just me.

 

[blaxsun]

My alkalinity swings within +/-0.25 dKH during the day, which I chalk up to the margin of error with the Trident.

 

[lemonade]

My KH swings between 6.5-7.5 non stop, and pretty much always has on all of my tanks. Makes the corals tougher and more durable imo. I've never seen any negative effects from this. If your swings are under .5dkh within 24hrs I wouldn't worry too much. Anything more than that you might start seeing some unhappy corals.

 

[jda]

It is fine. ...been happening for years. Consumption is different at different times of the day and some people only add at certain times of day. I have a 24/7 CaRx and if you tested at dawn and then again at dusk, the levels would be off by a bit.

I think that alk swings get blamed for too much and are right up there with 1). had something on my hands (motor oil, lotion), 2). neighbor sprayed for bugs or weeds, 3). roommate poisoned my tank and the like. I am not saying to let 10 dKh swings happen all of the time, but what is described in this thread is no issue.