man thats unlucky with your prefabed one, ah well least you have it to play with, although i havnet really looked at the RTC coding i would have thought it would be a pretty simple task to code it to turn on a relay and off at a certain point.
i did a quick search at probes today looks like i can pick up a PH probe for about £15-20 but trying to find any other types were pretty difficult.
but then i knew that really from looking at other projects.