Billy:

The simplest (and one of the ugliest) automatic topoff systems I ever
saw was on a tank in a dorm room at school. This guy Bruce (physics
grad student) had a sal****er tank with a homemade top-off mechanism -
no electricity needed. As best as I can recall:

He had a water container (it was like a 5 gallon water cooler bottle,
but GLASS!!!). I think he must have "acquired" it from one of the labs
; He had created a funky mounting system out of scrap wood to hold it
upside down on his desk, with the opening about 2 feet off the desk.
I don't know what kind of cork or stopper was in the bottle, but it
had two small tubes coming out of it. One was a J-tube that connected
to some plastic tubing that was taped to the bottom (now top) of the
jar, for a vent line. The other tube went to his fish tank.

In the fish tank (no sump) he had some kind of plastic tube with slots
cut in it that the water line connected to, and he was using a ping
pong ball for a float valve. When the water level dropped, the ping
pong ball sunk a little, and let water dribble out until the level
came back up enough to shut off the flow again.

I do remember that it was pretty finicky - he was always cursing it
out, and it flooded his desk at least twice... But it was certainly
simple!

Patrick



"Dinky" wrote in message link.net...
"Marc Levenson" wrote in message
...
| If you want gravity fed, the easiest thing is to get a container
that you can
| put up on a stand next to your tank. Drill a hole near the base,
and insert
| some type of grommet or bulkhead that allows you to affix some 1/4"
tubing
| without leaking. Home Depot sells that gizmo for evaporative water
coolers.
|
| Run the tubing to your sump, and affix a float valve in your sump.
As
| eveaporation takes place, the valve will drop and allow water to
gravity feed
| into your sump, and the float lifts back up to seal the line until
needed again.
|
| Marc
|

I'd really like to stay away from any more electrical components. I'm
already worried about how much I'm dragging out of this outlet as it
is, (return, tanklights, fuge lights, powerheads, skimmer, heaters)
and like I said, I don't want to buy much. Most of the options I'm
finding require installation of yet another water pump, or electric
valves.

I found this:
http://www-2.cs.cmu.edu/~cap/raid/to...hon/index.html

and I think I'm going to puzzle this one out. The bloody thing has
the description in the format of a bleeding IRC session, nut it's the
only thing that meets my apparently unrealistic criterion.

tyvm marc, john.


billy