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

Re:slow circulation

Mike writes:

<snip><maybe we could also use some sort of heater under the aquarium ..
>my idea is that to use some sort of steel plate stick to the bottom
>of the aquarium (outside) .. use some sort of heater to heat this up
>this might work like those food heaters .. in buffets .. where in
>the food is indirectly heated in a pan of hot water .. or maybe even use
>hot water .. then use a submersible heater set real high .. who knows

I believe this has been tried and more or less unsatisfactory results have
been obtained.  When you heat the entire substrate the desired convection
currents have trouble finding a stable "path", since the water is trying to
rise everywhere.  However, it seems to me, and this is pure conjecture, that
if you had a plenum (UGF plate) with a tube in one corner, and if that tube
had a check valve of some sort, so the water could only travel one direction
through it, probably best if it were down, then the water could rise through
the substrate and fresh supplies could come in through the tube.  Considering
the desired flow rate to get long "dwell times" in the substrate, a couple of
those airline checkvalves I have seen for aquariums might work if you machined
a plastic "plug" to stick in the tube, and drilled a small hole in the plug to
stick the checkvalve in.  That would allow the water to rise through the
substrate and drop down the tube.  You could put the under-tank heater on a
timer, with one hour on and one hour off.  This would tend to cause a slight
"vacuum" in the plenum when it cooled, and motivate the water to feed down the
tube (I think).

Bob Dixon