from what i have seen, that is a very good controller. i could not afford one when i was looking several years ago. i ended up getting an
Aquacontroller II. that has been just about perfect for me. it takes a bit of time to get used to the X10 stuff though. as long as all of the modules are on the same circuit or are very close you will have very few reliability problems. i have tank modules spread out all over the house and have to get filters and boosters to make sure my reliability is very good.
you should see how old the probes are. the temp probe will prolly last forever, no worries there. pH, orp, and conductivity can only last a year. it might be a good idea to check and see how old they are. you can still hook them up and calibrate them. it will not be long before you can tell how good they still are.
HTH,
G~
