Re: Aquatic Plants Digest V6 #48

[Jeffery Ludwig <jeff at rockytop_net>]

From George Booth and others:

>> I know 4 - 5 watts is optimum and
>> this is probably my best choice using that standard.
> 
> Where on earth did you read that 4-5 watts per gallon is optimal?
> 
> With modern, compact fluoresent lights and good reflectors, anything over 2
> watts per gallon is too much.
> 

I wonder why this issue keeps resurfacing?  We have all agreed that wpg is a
terrible measure of light, yet we continue the debate.  I disagree with both
of these statements.  4-5 wpg is overkill on a 100 gallon tank, but may be
appropriate for a 10 gallon tank and all of this depends on the specific
needs of the grower.  For those who don't think this rule can break down,
trying growing Didiplis diandra with 2-3wpg in a small tank and a large
tank.  I upgraded my lighting in a 15 gallon from 55W of PCF to 72W of PCF
to keep Diandra stems from rotting, I would like to see pictures of good
compact growth of this plant from a lower light, smaller tank if anyone has
successfully done this... maybe I am missing something?

Anyhow, my proposal is that we leave it like this:  use the least amount of
light that yields the color, compactness and robust growth you want out of
all of your plants.  If your glosso is growing vertical or stems are rotting
near the substrate or colors are not what you want, add more light. How much
light on your new tank?  Find the most light demanding plant in your setup,
and ask around about what has worked for others in a similar sized setup.
I'm not sure the APD is the right forum for this but certainly newsgroups or
message boards would be a great place to check.  Start on the low side of
suggestions and design your system with future upgrades in mind if they are
necessary.

Any thoughts?

Cheers,
Jeff Ludwig