Robert Walker <Robert.Walker@AIRSERVICES.GOV.AU> wrote:

> Is there a sensor that can measure pH that is cheapish and can
> say be connected to a PIC (similar to a DS1820 temp chip)?
> Also, is there a sensor which can measure the amount of CO2 gas
> in a given area?? again, it would be good to connect this to a PIC
> The reason is that I am interested in starting a little hydroponics
> set up, and any information on these (including the hydroponics :-))
> would be of great help.

I'm curious as to why anyone would wish to grow anything hydroponically
in a country with the climate of a greenhouse. Most of the population
is coastal and water is not _that_ scarce.

Hmm... call me Mr. Cheeky if you like, but you're not trying to set up
a cannabis growing establishment are you? I've seen ads for hydroponics
kits, usually selling halide lamps, etc. Somebody's got to want a plant
really badly if they want to force-feed it light and carbon dioxide.

Apologies if you're not, but you could always check out one of these
places. I'm sure they'll listen to your legitimate reasons for buying
it, and say "sure, what you do with it is not our business".

So, what are you up to?

Yours curiously, Mr. Cheeky.