Hello all

I've been reading this forum for years on way different subjects and learned so much! now i find myself growing things.

Anyways I'm implementing an automated aeroponics monitoring and water regulation system and need to find some pH and EC (TDS okay too) sensors to communicate with my microcontroller. 0-5V, 0-20mA, 4-20mA i can do em all.

Does anyone know of a vendor/story/place/link with these sensors that are cheap...and by cheap i mean under $50/e although i'm budgetting up to $125 per sensor.

I appreciate any help

Luis
-etxx


..for the record, its not only a water monitoring and regulation system its also the whole spraying, timing, moisture, water temp etc etc etc etc. Its my senior design project for december 08! attached is a rough sketch of the logic behind it all