"Dave M. Picklyk" wrote in message news:daUrc.14189$SQ2.6686@edtnps89...
Hi Tom, thanks for the insight...I never realized that about NO3 and lower
lighting. I have actually traded 3 really huge SAEs for 2 little tiny ones
(put them in my 48 gallon) so that takes out a big portion of the fish.

I have noticed that plants such as the Rotala do get a nice rosy color in
the last few inches closest to the light source. Right now I have a really
poor reflector (tin-foil that always get's crinkled) and I'll be upgrading
that to a mirrored acrylic reflector that I'm custom building to this shape
/¯\/¯\/¯\ . The bulbs right now are situated in an old aquarium lid that
only allowed a few inches of glass viewing area towards the back of the
aquarium...if anything this new design will spread the light more evenly
throughout the aquarium (especially the front).

Dave.

Red color close to the lights and redder color near tyhe tips= less
Chlorophyll in the new tissue. As this tissue aged, it turns green.
If the plant breaks the surface, it turns back to green again.
But it has more light..........so is it the light? Or the lack of
NO3?Or the rate of growth?

It's not just the light, don't assume too much about that.
I think people get into a lot of trouble when they assume a cause and
effect relationship means "that's why". The old "correlation does not
imply causation." It might suggest, but it does not prove anything.

The planted(and other aquarium specialities)hobby is full of myths due
to this.

You are wise to have "even" lighting, which is perhaps more important
than how much light/gal you have up to a point.

You can always do a dawn to dusk routine if you have the higher
lighting which will make things easier.
Careful about adding lots of light on the front= glass algae.

Better to pull the light back and tilt the reflector slighty missing
the glass but hitting the foreground.

You can see the plants redden up if you drive the NO3 down low.
Careful,n ot to stunt the plants though. This plant is pretty
tolerant, Mic umbrosum is not, it'll melt, get holes etc rapidly.

To drive the BNO3 down, add K+, PO4, CO2, Traces etc.
Don't use KNO3 as much or at all till things redden up and then
estimate about 1-2ppm a day of NO3 added. It's hard to say precisely
how much, a lot of other things deterimine NO3 uptake.

But low NO3, Nitrogen stressed plants will redden up, not due to iron
etc or high light, but due to the lack of Chlorophyll pigments which
make the plants green. Chlorophyll has a fair amount of Nitrogen. No
nitrogen, no chlorophyll.

Red color is from anthocyanin. It does not require iron directly nor
Nitrogen. Enzymes(which can be re used many times) involved in their
production use N and Fe but not the products.

It's main use is that of an antiherbivory rather than light
protection. But it certainly might help with high light, but our
lights are far less intense than the sun is and less UV etc.

More light combined with ore nutrients will increase growth rates,
therefore one could argue that's why there's more red, since the plant
has less time to add and assimilate the Chlorophyll enough to make
things green.

Some plants are primarily red also vs color variable species like most
Rotala, Ludwigia sp. Ludwigia and Rotala's are good for looking at the
NO3 effect.

Regards,
Tom Barr