Re: Aquatic Plants Digest V1 #37

> From: Patrick White <patbob at sequent_com>
> Date: Tue, 25 Apr 1995 14:25:21 -0700 (PDT)
> Subject: Re: Heating Pads
> 	This leaves the other effect(s?) of substrate heating as more
> important, namely the reducing environment.  I'd expect an unheated
> plain gravel substrate to provide this better than anything with
> circulation.  This would also suggest that a heating-pad aproach might
> be better than the heating cables as it would provide heat evenly
> enough to prevent circulation.

Yes it will be a great reducing environment, but after a time there
will be nothing worth reducing except sulphur compounds which produce
H2S.  The point of the cables is to also move fresh nurients into the
substrate to replenish the supply to the roots. 

Slow circulation is good; stagnant substrate is bad.  IMHO, of course.

> From: HoeschB at mail_fws.gov
> Date: Tue, 25 Apr 95 16:15:22 MST
> Subject: Java Ferns
>      I obtained a Java fern (Microsorum pteropus) and attached it to a 
>      piece of driftwood with a rubber band about 3 (almost 4) weeks ago.  
>      So far it is not doing anything...not dying, certainly not growing or 
>      producing new leaves.  Anyone have experience with this plant?  Do 
>      they take a long time to acclimate?  Once acclimated, how fast can 
>      they be expected to grow under good conditions (light, CO2, etc)
They are not fast growers but do very well in our CO2 injected tanks.
It's hard to tell how fast they grow since they sort of grow in all
directions at once, but ours get "too big" in about 6 months and get
drastically pruned.  We will cut sections from the rhizome with 6 or
so big leaves on it and reattach them to the wood or rock. 

Under bright light, Java Ferns really produce lot's of oxygen bubbles
- more so than any other plant we keep.

It seems normal for the older leaves to begin to go black when they
die.  At that time, little ferns sprout from the tips of the old
leaves.  We also get lots of spores under the larger leaves.  One time
when we removed a "too big" plant for trimming, we found a really
ancient dead leaf in the middle of the bunch and all the locations
where spores might have been had a little baby fern sprouting from it.

> From: ADAM.ARONSON at spcorp_com (ADAM ARONSON)
> Date: Tue, 25 Apr 1995 14:39:54 -0700
> Subject: Crypts Flower?
> V0FSTklORzogIEkgYW0gY29uc2lkZXJhYmx5IG5ldyB0byB0aGlzIGhvYmJ5ICh0aGUgcGxh
> bnQgcGFydC4uLikNCg0KDQpNeSBwbGFudCB0YW5rOiAzNyBnYWwuIHRhbmsgb2YgdmFyaW91

Is this something useful or a mistake?  Seems awfully cryptic to me

> From: jsprag at srv_net (John Sprague)
> Date: Tue, 25 Apr 95 19:22:56 -0600
> Subject: Temp. controlled DIY heat cables
> I am working on building a set of DIY cables for my 55 and was looking
> for a way to improve the recommended low wattage design that is so
> common.  I figured that the ideal is to have the cables provide all
> the heating in the tank, thus maximizing the convective flow and
> warmth of the substrate.

Too much heat in the substrate may be bad for the plants.  In our 90
gallon tank, we have a 250 w coil that usually supplies all the heat
to the tank.  When the tank water is 82 F (for discus), the gravel
around the coils is at 92 F and gradually becomes 82 F at the surface
of the gravel.  This may be too warm for some plants.  300 w in a 55 
may be major overkill.   

In our 100g discus tank with 100 w coils, the gravel temp varies from 
85 F at the bottom of the gravel to 83 F at the top.  This seems more 

In the 90 g tank, the coils cycle on and off a lot and tend to be off 
for hours at a time.  In the 100 g tank, the coils are on almost all
the time.  I would conjecture that constant warming is better than 
sporadic warming. 

Our first tank with coils (the 90 g) was setup before much was known
about them.  The Dupla recommendation was 150 watts (based on a temp
of 76 F).  We were going to keep discus (82 F) and the tank was going
to be an open top and it was in a cool room, so we figured more
wattage was better and bought a 250w setup.  The cable size, unknown
to us, is based more on tank dimensions than anything else and was too
long.  This required us to install it with a closer coil spacing than
was "standard" (based on the Dupla anchors).  BTW, the 250w coil was
not sufficient to maintain the temp on colder nights; an Ebo-Jaeger 
200 w heater was also needed (room temp was 65 F).  

> My plan is to take a 300 Watt Otto compu-therm heater and hook the
> supply for the transformer up to the control box instead of the otto
> heater.  Voila, instant probe and controller.  The cost of it is
> $30.00, which is less than I would have paid for another heater to
> make up the difference in the required wattage and a timer to control
> the intervals on the cables (if it would have ended up being
> necessary).

Keep in mind that a 300 w cable running at 24 volts requires a 12.4 amp
transformer (minimum; a 20% margin would be smart, i.e., a 15 amp 
transformer).  Have you tried to locate a 24 v, 12 amp transformer? 
Good luck.  Dupla has one that they will sell you for $250.  Voila :-)

> From: BobWurster at aol_com
> Date: Tue, 25 Apr 1995 22:57:05 -0400
> Subject: Re: use of epoxy resin for heating cables
> >I will be investing in the 20lb. bottle and regulator per. >George Booth's
> >FROG dingus later this year.
> Can someone enlighten me as to the exact nature of a
> FROG dingus? I'm new here.


The best is a two-stage regulator designed for use on welding gas
cylinders.  This reduces the 950 psi tank pressure to 10-20 psi.  You
can get a cheap fixed-pressure regulator with no gauges for about $45
from places that have beer brewing supplies.  The lowest cost is a
Flow Regulated Orifice Gauge, FROG, and puts out a constant pressure
(22 psi or so).  These are available from welding shops and are cheap
but there are no gauges so you don't know when the bottle is about
empty.  Without gauges, you'll just be surprised some day when you
check the controller and find your pH is 8.2.

George Booth                         "Nothing in the world is more dangerous 
booth at hplvec_lvld.hp.com             than sincere ignorance and conscientious 
Freshwater Plant Tank Technology     stupidity" - Martin Luther King, Jr.