Adblu warning again

[RogerWill]

Was returning from wildcamping in scotland.
At7900 miles the adblue warning came on advising 950 miles( till empty/ wont start).
At 7950 filled up with a litre.
Next day back home 8350 miles, still 950 mile warning.
Bought 2x10 litre tubs adblue.
Used all of one tub 4 days later
Warning still on.
A further 5 days and a booking in to my dealer for 14 days time
950 mile warning still on
Drove 170 miles to Westward Ho.
WARNING NOW GONE and been gone for 6 days.
QUESTIONS
1)How foes the adblue re set?
2) My manual says the adblue tank is 17 litres, since the warning started I filled 1 litre, then 10 litres, then 1 litre from a 2nd 10 litre tub.Thus it seems there was 4 or 5 litres left in the adblue tank when the warning came on.
3)Is it likely that the warning initiated because of the terrain ie up steep hill(s)( Scotland) thus falsely triggering the warning.
4) I will cancel the dealer booking as there is no sign of the fault AND every time I take a car for warranty issues, they ALWAYS advise £90 if they cannot find the fault.
For this car been in 4 times for re- booting various errors/ warnings/ missing dash lamps 8e auto lights, auto wipers,lane warning.
My previous car an i20 had 10 trips for warranty issues, all but one fixed most not fixed till the car was looked at by a considerate technician, the worst delay was a complete steering column change as a motor or simmilar FAILED on the first day, took 2 years to be replaced.- Richmond Portsmouth - who now are not a Citroen agent, but still a Hyundai one

[dellwood33]

i was told that it needed a minimum of a 5 litre top up to reset the alarm warning.
I have only done 37 miles, so hopefully a long time before I need to top up - having said that there appears to be no way of checking the level, so I don't know exactly how much adblue is in the tank.

[Desdinova]

Warning came on for me at 3200 miles.

Bought a 10 Litre container from Halfords, filled up the tank - it took the full 10 Litres, and warning disappeared on the dash within a minute.

Oddly the warning on the My Citroen App on my phone took 24 hours to go though.

Online instructions do say minimum of 5 Litres when warning comes on but Halfords advised that most cars actually will need 10 Litres when I asked.

[boop]

I have just filled it up at the petrol station pump and the message has disappeared.

[RogerWill]

For not / hind sight after the above tip I bought 2x15 litres of we you for £15 Inc postage enough for me not to worry for many miles, I just top up now and again methinks it's better in the car tank than in its container- refering too it's theoretically quite short shelf life