"Fill to Here" device in Harvest Elite

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Last seen: 5 years 1 month ago
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"Fill to Here" device in Harvest Elite

I'm cleaning my (wonderful) Harvest Elite for the first time.  My Basil had roots and roots and roots.  They got into everything so I took out the pump, took it apart, got rid of the roots and put it back together with no trouble although I've found no directions.  Then I pulled off the tube labeled "Fill to Here" and found out that inside it was a gizmo with a wide end made of clear plastic and a narrow end with metal.  I've taken two photos - see attached.

My assumption is that the deice I'm considering a float should go back in the tube with the metal end down and the larger part up.  BUT... that is an assumption and I haven't found anything that agrees with me.

So...  please help.  Clearly if I get it wrong the Add Water light won't come on.

Thanks in advance and a Happy Easter.  :)






Photo 1 "Fill to Here" float
Photo 2 "Fill to Here" float
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Ginger's picture
Last seen: 9 months 1 week ago
Joined: 2008-06-23 15:55
I may have to check that out.

I may have to check that out. My tomato LED Ultra add-water light is on all the time these days.

Moderator. Author of Indoor SaladEcigs 102, and the Calm Act climate apocalyptic series.

HardwareJunkie's picture
Last seen: 3 years 6 months ago
Joined: 2015-12-14 11:45
So the metal part is actually

So the metal part is actually a magnet. And that part goes to the bottom part of the tube.

It floats when you add water and when it gets close to the bottom, it gets close to a magntic switch in the base that triggers the low water warning.

Last seen: 5 years 9 months ago
Joined: 2016-01-04 10:08
There's really only two ways

There's really only two ways a device like this can work:

1.  Conductivity.  When water completes the circuit, the Add Water light won't come on.  When the metal goes dry and the circuit is broken the Add Water light comes on.

2.  A float.  Obviously the metal part doesn't float.  The plastic part could.  The metal part is there either to complete a circuit with contacts (doubtful as it seems to be entirely encased in plastic) or it is magnetic and its position is sensed by a sensor (what's known as a Hall effect sensor, though it could be something more primitive like a magnetic reed switch).

My bet is the latter.  This assembly looks completely encased in plastic, there doesn't look to be a way for a conductivity probe to work, it needs exposed metal contacts.  So I would guess the metal pellet is actually magnetic (is it?) and its position is detectable, it either triggers a reed switch or a sensor at a certain position.

Does the metal pellet flop around inside when you tilt the assembly back and forth?  Is there any workings exposed around the spot where the "fill to here" device attaches?  (The reed switch/sensor could be mounted just underneath the assembly under the tank floor where you can't see it.  It will work through plastic just fine.)

I would guess the sensor is in the tank floor and detects when the pellet drops to the bottom.  The float pulls the pellet up when there is water in the tank.  Therefore I'd reinstall it with the pellet at the bottom.