I want to start a computerized monitoring system

[Blue-Wolf]

As the title says, I want to start a computerized monitoring system. I have a Windows XP computer that is doing nothing at the moment, and it has 3 USB ports available, which I am hoping to use for the probes, if possible.

What I want to monitor are PH, Salinity, and calcium.

So I guess my questions would be:

1) Is there a program which will run in Windows XP that will monitor these?
2) If so, which program(s)?
3) Where would I get the probes I need?
4) What would be the cost of the program and the probes?
5) Will I loose my mind if I try to set something like this up?



Any and all help is appreciated.

Thanks.