I'm getting back into the hobby after being away for a while and I
decided to set up a 6'x2'x2' planted freshwater tank with substrate
heating cables. I've been reading everything I can look up on The Krib
and other sources and I decided to go with the 250 watt Dupla cables
(Duplaflex 1000), even though they cost an arm and a leg. Now the
decision is the power supply. Does anyone know of any good sources for
one that is sufficient to power these cables that won't cost my other
arm and leg or should I have to bite the bullet and spend another $200
for the Dupla one (http://www.floridadriftwood.com)?

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?

If I do end up going with the Dupla transformer, does anyone know if
that will only connect to the Dupla temperature controller or can I use
some other controller (Neptune's AquaController II, for example)?

Thanks for any info on the subject!

- Allan

In article MPG.1bd65c6ac2a9eb7f989682@news-server, ty1xlnf02
@sneakemail.removethis.com says...
...

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?



Tortran ( www.tortran.com ) makes nice toroidal transformers in that range. They
have a 300VA version and another at 500VA. (VA and watts are equal for a heater.)
These have two secondaries of 12V each, so you would connect them in series to get
24V output. The 500VA model is only $67, but comes without a box or anything, just
a large transformer with wires brought out. If you want to put one in a box
(recommended to protect your connections from getting wet) be sure to get the
mounting hardware.

If you like ebay you could possibly find one there too. 120V input, 24V output
transformers with high current ratings are fairly common.

Allan wrote in message news:MPG.1bd65c6ac2a9eb7f989682@news-server...
I'm getting back into the hobby after being away for a while and I
decided to set up a 6'x2'x2' planted freshwater tank with substrate
heating cables. I've been reading everything I can look up on The Krib
and other sources and I decided to go with the 250 watt Dupla cables
(Duplaflex 1000), even though they cost an arm and a leg. Now the
decision is the power supply. Does anyone know of any good sources for
one that is sufficient to power these cables that won't cost my other
arm and leg or should I have to bite the bullet and spend another $200
for the Dupla one (http://www.floridadriftwood.com)?

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?

If I do end up going with the Dupla transformer, does anyone know if
that will only connect to the Dupla temperature controller or can I use
some other controller (Neptune's AquaController II, for example)?

Thanks for any info on the subject!

- Allan


I'd suggest you not add a cable system at all.
I've never found them after 10 or so years(I've had 7 over the years
by Dupla and others)to be of any use. Do they hurt? No, do they help?
No.

I'd work on the substrate by using Flourite or Onyx, add some mulm
from another tank, about 8-10 handfuls of ground peat and add 3-4"f
these syubstrates on top of the mulm and peat.

Then you are done.
Nothing else needed.

You can search the APD for my arguments on cables and find some back
and forth between George and myself over the years.

No one to date has even come close to answering my questions
concerning them nor shown any evidence that they work.

I think "faith" has more to do with it than actual help to the
plants.
It will work if you believe it works

You will find a significant difference with a good substrate like I
suggested though.

Regards,
Tom Barr






Regards,
Tom Barr

I would check with dupla and make sure another power supply will work.
I really am not sure about this with their thermic sets heating.
Usually as long as the power settings are the same and the end piece
is you wouldnt have a problem
Marc
__________________________________________________ __________________________________________________ _______
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On Wed, 13 Oct 2004 03:28:58 GMT, Allan
wrote:

I'm getting back into the hobby after being away for a while and I
decided to set up a 6'x2'x2' planted freshwater tank with substrate
heating cables. I've been reading everything I can look up on The Krib
and other sources and I decided to go with the 250 watt Dupla cables
(Duplaflex 1000), even though they cost an arm and a leg. Now the
decision is the power supply. Does anyone know of any good sources for
one that is sufficient to power these cables that won't cost my other
arm and leg or should I have to bite the bullet and spend another $200
for the Dupla one (http://www.floridadriftwood.com)?

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?

If I do end up going with the Dupla transformer, does anyone know if
that will only connect to the Dupla temperature controller or can I use
some other controller (Neptune's AquaController II, for example)?

Thanks for any info on the subject!

- Allan

In article , sales@aquatic-
store.com says...
I would check with dupla and make sure another power supply will work.
I really am not sure about this with their thermic sets heating.
Usually as long as the power settings are the same and the end piece
is you wouldnt have a problem
Marc

I'll check, but I'm not sure Dupla would really give me an honest answer
to this question if their goal is to sell their own transformer?

In article ,
says...

I'd suggest you not add a cable system at all.
I've never found them after 10 or so years(I've had 7 over the years
by Dupla and others)to be of any use. Do they hurt? No, do they help?
No.

I'd work on the substrate by using Flourite or Onyx, add some mulm
from another tank, about 8-10 handfuls of ground peat and add 3-4"f
these syubstrates on top of the mulm and peat.

Then you are done.
Nothing else needed.

You can search the APD for my arguments on cables and find some back
and forth between George and myself over the years.

No one to date has even come close to answering my questions
concerning them nor shown any evidence that they work.

I think "faith" has more to do with it than actual help to the
plants.
It will work if you believe it works

You will find a significant difference with a good substrate like I
suggested though.


Tom, I had previously read your post when I was doing my research and I
agree that no one has proven beyond a doubt that cable heating is
critical for a planted tank, but going off the anecdotal reports of a
couple of other people that said they were going strong for 12 to 18
months and then growth tapered off mysteriously. After setting up a
similar set-up with the heating cables which resulted in a more stable
system in the long term made me lean toward trying them out.

I haven't done much research on Flourite, but I'll bone up on it prior
to making a final decision.

Thanks for your reply, though.

-- Allan

In article ,
says...
In article MPG.1bd65c6ac2a9eb7f989682@news-server, ty1xlnf02
@sneakemail.removethis.com says...
...

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?



Tortran ( www.tortran.com ) makes nice toroidal transformers in that range. They
have a 300VA version and another at 500VA. (VA and watts are equal for a heater.)
These have two secondaries of 12V each, so you would connect them in series to get
24V output. The 500VA model is only $67, but comes without a box or anything, just
a large transformer with wires brought out. If you want to put one in a box
(recommended to protect your connections from getting wet) be sure to get the
mounting hardware.

If you like ebay you could possibly find one there too. 120V input, 24V output
transformers with high current ratings are fairly common.


George,

Here's my thread with a contact at Tortran:

Me "I'm interested in using some 250 watt 24 V substrate heating
cables for my aquarium and I need a step down transformer to power the
250 watt cables where the primary is 115V 50-60Hz, 2.9A and the
secondary is 24V Max, 12.5A and the windings are completely isolated
from each other. Do you sell anything like that? If so, could you let me
know what the price is? Thank you for the information."

Tortran Rep "Hello Allan, thank you for your inquiry. We have two
alternative designs for your consideration.

P/N B300-2 at $39.95
P/N R300-2 at $100.75

Prices are FOB factory in Bridgeport, CT.

These are both 300VA (24V at 12.5A) transformers. They come with dual
12V secondaries that you connect in series to get 24V. The R-model is
mounted inside a box and has a resetable fuse. If you go to our website
and click on standard transformers and then on lamp transformers and
scroll down you will see an illustration of the enclosed version for
remote installation."

After going to their website, I'm trying to figure out what is
contributing to the $60 dollar difference in price between the B and R
models. It looks like the R model has the following description:
Transformers mounted inside a white steel enclosure with automatic
circuit breakers for remote installation. Enclosed transformers are UL
listed. Input voltage 120V/60Hz. Single output voltage 12V under 300W
and dual 12V For extra safety we have added auto-resettable thermal
cut-offs inside the transformers between the primary and secondary
windings.

Is that worth the extra dough, or would it be easy enough for a layman
to by the bare transformer and build a box with $15 worth of Radio Shack
components?

Thanks again.

Tom, I had previously read your post when I was doing my research and I
agree that no one has proven beyond a doubt that cable heating is
critical for a planted tank, but going off the anecdotal reports of a
couple of other people that said they were going strong for 12 to 18
months and then growth tapered off mysteriously. I haven't done much research on Flourite, but I'll bone up on it prior
to making a final decision.

Thanks for your reply, though.

-- Allan

Uhmm. there is no mystery as to why a tank's plant growth slows down,
there are 3 main components and if you address these, you will not
have slow down or otherwise any monkey business with plants at all.

Growth is driven by 3 main things in tanks: Light, CO2 and nutrients.

3 things.

Cables are not one of them.

I think the real issue is that the tank slows down due to other
factors, low CO2, less light(bulbs change color over time and
intensity), nutrient status etc.

If these are not addressed, then there is no test and it is pure
speculation. I'm one that does do critical approaches to plant growth.

If you devise a test to answer a question, you need to make certain
the test is not influenced by otherwise factors, things like CO2,
lights, Nutrients.

You wish to test only one dependent variable, any other things like
light/CO2/Nutrients variations must be in good shape or will
invalidate the test and you must start over again.

I got good at maintaining the water column, the light/CO2 are rather
easy once you figure that out.

So then you can go about testing much more critically and see if there
is any merit to a method/device/idea/theory. You also can see how much
interaction it has with other methods. You can simply go down the line
and test each nutrient, light set up, substrate methods, etc one at
time and not have it be influenced by the other parameters.

Any hobbyist can do this and prove things to themselves, which I've
always told folks to do if they really care that much about the issue.

I also suggest folks look critically in the background research and be
careful to look for research that is directly as possible applicable
to the given situation. I did RFUG's, cables and no flow series(plain
old flourite and no mechanical flow) through substrates over the
years, I have about 10 years in each method.

I have a long background both experimentally, practical, and academic
in specifically dealing with substrates. George is a smart guy and
nice guy BTW. Still, he's considered switching to Flourite as well.

So......

You might consider adding flourite to a cable system also.
I've not done this combo, but I get better growth than anyone with
cables as it is so I really don't find the need.

I stick to the core basics, light, CO2 and nutrients.

Still, the question is will cables hurt? Nope.
So you are not making any mistake, just wasting your $ is all.

If you add ferts to the substrate, cables will oxidize them faster
than no flow set ups. Likewise a RFUG will oxidize them even more so.
Anyu increase in the flux will increase the redox levels(further
oxidizing the nutrients) and providing faster bacteria to use the
nutrients.

I've argued that these aerobic bacteria are the main driving factor in
cycling besides the plants.

But.......plants still kick the bacteria's butt on uptake of NO3, PO4
etc.
So it still gets back to the big 3, light, CO2 and nutrients.

Take care of the plants, the rest is not an issue.

Regards,
Tom Barr

In article MPG.1bd8f28faa06c35c989685@news-server, ty1xlnf02
@sneakemail.removethis.com says...
In article ,
says...
In article MPG.1bd65c6ac2a9eb7f989682@news-server, ty1xlnf02
@sneakemail.removethis.com says...
...

Even though I don't have much electrical engineering experience, I'm
open to trying some of the DIY options I've read about. Anybody have any
recent experience with that? Anybody know of any good places to get low
voltage/high current (24 V @ 11+ A) step down transformers?



Tortran ( www.tortran.com ) makes nice toroidal transformers in that range. They
have a 300VA version and another at 500VA. (VA and watts are equal for a heater.)
These have two secondaries of 12V each, so you would connect them in series to get
24V output. The 500VA model is only $67, but comes without a box or anything, just
a large transformer with wires brought out. If you want to put one in a box
(recommended to protect your connections from getting wet) be sure to get the
mounting hardware.

If you like ebay you could possibly find one there too. 120V input, 24V output
transformers with high current ratings are fairly common.


George,

Here's my thread with a contact at Tortran:

...
Is that worth the extra dough, or would it be easy enough for a layman
to by the bare transformer and build a box with $15 worth of Radio Shack
components?


Sorry for the late response. The wiring is very simple and you should not have any
trouble building it yourself. Instead of a thermal cutout, which protects against
transformer overheating from too great a load, you can just put a fuse in series
with the transformer primary. A 3A, 250 volt slow-blow would be about right for
your 300W application. Whatever you do, please be sure to take some steps to
prevent water from getting in your box and defeating the insulation. I use a GFI
in the wall but would also ground the box if it is metal.