Nocturnal change problem?

[Gael]

Hello,

On my fresh water tank, PH sensor is set Nocturnal change to yes with change of: -1, starttime: 21:00:00, endtime: 09:00:00.

Now, it's 13:21, Ph actual value is 5.15
Nominale value 6.50
Hysteresis 0.20
Alarme Active, deactivate control:no, max deviation: 0.50

-> If I set Nocturnal change to no, alarm ring!

But at 13h21 we are not in the 21:00:00 - 09:00:00 period.

What i do wrong?

Thank

[Matthias]

No, there is no nocturnal change problem

the alarm limits include of course the nocturnal change, all the day, because the actual value will not change immediately just because the nominal value changes

see manual

https://www.aquariumcomputer.com/dow...g-guide-v6-15/

[Gael]

Hello,

I already read the manual, it say nothing about alarm with nocturnal change.
But now I understand, nocturnal change is only for people who use profilux output for increase / decrease ph, temp, redox etc... not for setting max deviation of ph for exemple to the minimum without having an alarm the night (because of dark )

Thank Matthias.