I was in Europe for the last 6-weeks of Grad School (2006) but had a controller hooked up to the internet so I could monitor the tank.
- any pH swings indicated that my Kalk reactor was acting up.
- any salinity swings indicated that my auto top off was out of whack.
- any temp swings pointed to heater or chiller malfunctions.
- any orp swings could mean a dead fish in the tank or over-feeding, etc.
Having a responsible Tank Sitter who at least understands the basics is absolutely crucial.
However having 24/7 access to all of the above mentioned perameters really set my mind at ease.
Enough to certainly justify the cost of controller and hookups.