My thermistors were 55 cents each. I'm OK with using a buck's worth of epoxy to pot them. just shouldn't have used the epoxy PUTTY, or should have used more of it. (since one sealed OK and one didn't) and, 100k @ 25C thermistors were what Dataq recommended on their web page, though the exact part they recommended, the link is bad.

The last time I had to waterproof something for electronics, I used some liquid tape.

http://www.8051projects.net/downloads209.html

This is my first post here so sorry for if I repeat any information that is already on the site. I really like this site so far and I will continue to read and find out if growing is really worth it.

Now for my relative information. I know of a company that sells PLC's with built in I/O and free software for cheap! Base model priced around $250! Everything can be done from this little guy and best of all anyone with very little technical knowledge can do it. Its all based off ladder logic and it can even display values, datalog, and trend! It comes with 8DI, 8DO, 2AI, and 2AO. With this I/O anything can be done. It also has built in communication for Serial, Modbus and many others. You can also buy expandable modules for almost unlimited I/O for cheap.

If I do plan on growing, I'm defiantly using this! There is so many possibilities.