Top up question

[Ruth]

I run my tank and refugium with open tops so I get a fair amount of evaporation - like 5 gallons every 2 days. I do not have a basement so my fuge/sump is set up right under my display tank and there is not a lot of clearance.
Does anyone have any ideas on setting up a top up system that could be used with this set up? I travel quite a bit with my job and frequently have to be gone for a couple of days. I usually get the neighbor to come in and dump a 5 gallon jug into my sump every other day but I am going to get stung one of these time and burn up my return pump and skimmer pump.