sufficient lighting?

[aquascapist]

HI guys!
This is regarding a friend's planted tank. He has it setup now for close to two months.
Dimensions:
L-56 x D-24 x H-27.
Lighting is from 2 x 150W metal halides(10000K) suspended 19 inch from the top/surface of aquarium.
Substrate is flourite. Presurised CO2. EI ferts.
He is consistently dealing with algae mostly diatoms and hair algae along with poor plant growth. Even growth from fast growing plants like rotala rotundfolia, hygrophila difformis is pretty slow. Was wondering whether it is due to wrong light spectrum and/or insufficient light due to height?
Thanks

[maaz]

What about filtration...

[aquascapist]

oh forgot that! he's got an eheim 2217 and a separate sump with bio balls.

[Matrix]

Tank snap will be more helpful to comment.

[SCORPIO]

I think spectrum of light is culprit for slow growth of plants. 300 watt light is enough for this tank although height of tank is 27 inch. Your friend is using fertilizer and CO2 along with high light. Plants should be grow speedly. Advice your friend to change bulbs of MH. Also install 2-3 power heads in the lower parts of tank for good circulation of water.

[aquascapist]

ok attaching couple of pics he sent me

[aquascapist]

and some more

[aquascapist]

full tank shot

[aquascapist]

I think spectrum of light is culprit for slow growth of plants.

I've since asked him to change his lights to 6500k. I also read at other forums that higher spectrum tends to induce more algae.

[SCORPIO]

The upward growth and thin stem is the sign of insufficient light.