[Stoots]

I don't use a controller either but in 6 hours 500l is more than enough.

You must be doing some graft or literally not turning your water off at all whilst on a job, are you just spraying it everywhere constantly?

Most days I use about 400

[Go]

Fill up with what you have now and go over a weigh bridge. Then you’ll know for sure.

[windowswashed]

Must have a lot of large glass to use more than 650 litres. Commercial all day use 600 litres, long tiring day.

[Walter Mitty]

I had a similar van (Trafic) and it had a 1200kg payload.  800 litres in the tank was right up to the limit (I checked at a weighbridge).  But I also had a ladder and a few other bits in there which added to the weight - plus I'm not so light myself.  The Trafic was the type that had a 2.9 tonne gross weight.

[dazmond]

rule of thumb is the tank should be around half the payload of your van.so if your tank is 500L then you should have a 1000kg payload van....mines slightly under at 936kg plus i have a diesel heater fitted but still ok....

full tank 500kg
frame  20kg
reel  15kg
diesel heater 100kg
2 batteries 40kg
ladders and roof rack 10kg
trad gear and bucket 10kg
 tank of fuel 50kg
me 114kg
poles and holders 5kg

=864kg so still 72kg under......(and getting lighter as the day goes on)

[Walter Mitty]

The rule of thumb I've always used is water weight to be at least 500kg less than payload.  For that reason, whenever I wanted a full 800kg in my 1200 payload Trafic, I ensured the diesel was fairly low in advance and I removed some of the heavier unneeded  stuff from the van.  Some will get away with a tighter margin if they are lighter in body weight and don't carry much in extra equipment anyway.