Since this is going in a public space and you never know who will mess with it I would get a battery operated digital thermometer preferably with alarm as sometimes people unplug stuff and forget about it.
Do post instructions next to it on who to call if there is a problem-a school here has a tank and they don't ever call consequently have had all the fish replaced several times over for every conceivable reason. Also let maintenance know not to use sprays or pesticides near the tank, preferably not in the room or near the windows outside.
A simple alarm can be installed to tell you if the tank, skimmer or sump is overflowing. Powells Technical Books in Portland sells them as a 6 buck kids toy "rain alarm" but I cannot find them anywhere else which is pretty annoying... Maybe your science dept can help with this idea. This sounds like the same idea:
http://xtronics.com/kits/SK-108.htm
Wonder if you can get the science dept to rig up a ph monitor and program a recycled computer to ring your cel phone if the ph, temp, etc shifts? Sounds like a great project for the students... and justifiable valid applied science experiment. I don't know what grades/abilities you work with, if you can make this happen share the results with us eh? Can you make it Linux ?
I use temperature controllers/thermostats for heaters, they have much greater precision than what you get with a typical heater. Heaters fail either on or off, one way means fry your tank with heat and the other by chilling. If you have two heaters and one fails will you notice? How long will the 2nd heater last if it was bought at the same time and is suddenly doing the work of two? Most of the heaters I have bought have failed within a year of usage, usually in the on position. Plus most heaters have the thermostat mounted right above the heating coil so if there is not flow across it the water rises when heated and tells the thermostat the tank is warmer than it is. Most also don't turn on or off til a 2 to 4 degree temperature shift which I believe is not acceptable when the lights are already shifting things around enough to stress the animals.
At the bottom of this page they explain it better than I do, I like their pro gear but I use $15 Otto thermostats from Angels Plus because I am cheap
http://www.jehmco.com/PRODUCTS_/HARDWARE_/Temperature_Controller/temperature_controller.html
http://www.angelsplus.com/ go to store and look under heaters for the otto temperature controller.
I don't know if these guys would donate or cut you a deal. There is a well known brand of titanium heater with remote thermostat attached which I don't recommend, two caught on fire that I know of and they cost too much, if either the thermostat or heater breaks you throw both away, I don't like that.
Above all I would quarantine at home and be very very careful. Post a sign that nothing goes in the tank, if someone wants to make a donation they need to clear it with you so you don't end up with surpise "gifts". (unwanted damsels and freshwater fish) Some people think you can mix freshwater and saltwater if you are "careful". Part of this is because a certain box store or two tells it's employees to answer all questions with "yes" or be fired... I heard one employee tell a lady if she kept it at ph 8.4 she could keep a marine angel with freshwater cichlids, so you never know what people will think are ok to put in your tank. Cichlids in the marine tank, they can last a day or two... A friend found a sandwich in his sump that a kid tossed in. He said a couple Magnum 350's and a lot of carbon took care of that. Guess it couldn't hurt to have water, cleaning gear and supplemental filters set aside for emergencies like that.
One fund raiser you could do is to have parents donate tank gear they don't want for you to ebay off. Lots of people have aquariums in the garage. Keep the magnum 350s.
Good luck! I have mushrooms and kenya tree corals galore if you go soft coral... let me know, I will mail you some.
Kate
