mih vs. cfl lighting in small freshwater tank

[souter]

First off, apologies from a new member if this is answered elsewhere.
I've got a 2' tropical freshwater tank essentially dormant. What I want is vibrant plant growth. Currently the tank is unheated in a south facing centrally heated Irish bedroom. Average temp is c. 70 fahrenheit and the sole occupant is an indestructible red tailed shark, a few scabby crytos, amazon sword and some algae. Only filtration is an internal sponge type yoke, subsoil is pea gravel, essentially zero nutrients going in.

I was brought up to believe excess light caused algae, but I have a theory that sufficient light + sufficient nutrient will allow higher plants to outcompete algae. Accordingly I've been trying to upgrade my standard single 18' tube to no avail.

I'm now looking at homebrew solutions, either with multiple CFL lights or a 35/70W metal halide.

The tank is in a chimney breast so there is potential to install something like http://213.200.67.110/web05/product-details.asp?pcode=R1180-01 (circular fitting for 18/26W G24q2 CFL bulbs) * 2 for CFL or even http://213.200.67.110/web05/product-details.asp?pcode=R150R (rectangular fitting for R7S bulbs) for HID.

I'd be restocking the tank with a few more fish, though the plant display would still be the priority.

I'd be interested if anyone has tried any similar lighting configurations, or would be able to tell me other things I should be looking at to achieve my dream of lush aquatic growth.

Thanks,
John

 

[czcz]

Welcome to AA.

What size is the tank in terms of gallons or liters? I think to do this right you will have to modify or replace the reflectors to focus light into the tank. How high up are the lights?

Check out the planted tank forum here too. The stickies and discusion are from people who know this to be true:

sufficient light + sufficient nutrient will allow higher plants to outcompete algae.

I think you will find high light planted the most rewarding.