1 watt per gallon is perhaps too small - for any plant to be happy
(especially grasses and red-ones) you need about 3 W/gall
The tank is also 2' (60cm approx) tall - so the intensity of light at the
substrate will fall off more rapidly with deeper tanks - I would suggest
some high intensity tubes as well.

I have a 50 cm high tank 3 tubes with a total of 90W over 250L(66gall) gives
at minimum 1.36W/gall at maximum with parabolic reflectors lets say about
2W/gall. I have trouble keeping algae off the grasses as the grasses don't
seem to want to grow that fast (I use CO2 as well). Some red plants are
actually only red towards the surface and cabomba is not flourishing - it
has long inter-node stems.#

So at 50cm deep 2W/gall is insufficient - funnily enough even the Crypts are
showing hair-algae growth - and they should be low light plants.

I am considering getting Hagen PowerGlo at 18,000K temperature they peak in
the blue spectrum and this should penetrate water to a deeper level. Here's
hoping.

Martin

"cw" wrote in message ...
Is there any chance that 4X 36W PL light be able to keep any plant happily
alive in a 5'X2'X2' tank ?