Lighting too much or too little?

My Tank is 48x18x24 deep so I've got about 20" of water depth. Its got a
sand substrate, Cannister filters and CO2 injection from a gas bottle which
is controlled by a Ph meter. Rough calculation says about 20ppm CO2.

Over the top are 4x42" 40W tubes with reflectors on them & glass
condensation covers which are kept clean & scale free. The Tubes are 2 Hagen
Life Glos, An Aqua Glo and a Power Glo

I don't have any Algae to speak of - a Few bits of the black spotted stuff
on my Annubia leaves is about all.

The lights are on for around 12 hours a day.

My question is this, I recently acquired a Cabomba type plant (its not
regular Cabomba but very similar) from My LFS They have it growing in a
similar size tank & their is growing very densly.

Mine (and my Red Cabomba for that matter) is very "leggy" i.e. long stems
with big gaps between the fern bits. All my plants grow like mad anyway but
I am beginning to wonder if in fact I've got my lighting a bit wrong. I am
wondering if there is not quite enough of it which is why the plants are
stretching upwards towards what light there is. I just use off the shelf
plant food fairly regularly & monitor it by keeping the Iron level in the
range it should be.

Anyone have a view on this?

rgds

Iain

Mine (and my Red Cabomba for that matter) is very "leggy" i.e. long stems
with big gaps between the fern bits. All my plants grow like mad anyway but
I am beginning to wonder if in fact I've got my lighting a bit wrong. I am
wondering if there is not quite enough of it which is why the plants are
stretching upwards towards what light there is.

I doubt that's the problem. "Leggy" Cabomba (long internode length) is a
common, even in high light tanks. In fact, IME, it's more common in high
lighting. It grows a lot bushier in my moderate-light, non-injected tank than
in my high-light tank, I think because it grows slower.

One thing that can help is to never "top" Cabomba. Don't just chop the tops
off when you prune. Instead, pull out bottoms and re-plant the tops. That
helps a lot in keeping it bushy.



Leigh

http://www.fortunecity.com/lavender/halloween/881/