DD, about to turn 13, is really into marine life, oceans, sharks etc and has her heart set on some kind of coral set up in her bedroom. I'm fairly comfortable with the idea but not sure about ongoing costs. She's looking at a nano tank, c 60 litres, and is primarily interested in coral but could I guess add some fish later. We've been to a shop and had some advice re importance of the lights, skimmer etc. I'm concerned about ongoing electricity costs (about £50-80 a year I've read?) and the ask if we go on holiday - would we need someone to come into our house every day to feed and top up water, then potentially do a water change if we're away longer than a week? It all sounds a bit fiddly for me, the testing of the water etc but that's probably just me!