[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


At 03:48 AM 12/13/98 -0500, Dennis noted:
> So far my only problem was when I tried to use a solenoid to shut it off
at night
>the one I used only reduced my flow and leaked.  So I'm now running it 
>24/7 until I solve the solenoid problem.

Right on, Dennis.  This is a major problem with solenoids.   There are two
solutions (as usual):

1.  Spend the $$$.   I am guessing a bullet-proof, never-fail,
works-perfectly-forever solenoid with a similar power supply is about $100.
 Of course, that neglects the cost of the timer, pH sensor, or whatever.
And bullet-proof pH sensors do not exist in my experience.

2.  Expect failure and build a failure-tolerant system.  This is the idea
of the current project that 8 members of this list are helping me with.  I
hope to come out with a $12 solenoid (includes power supply) soon.  You
will need to add your own timer.  I will not approach pH control, it isn't
worth it for plants.

Dave Gomberg, San Francisco            mailto:gomberg at wcf_com