Suitable Lighting tubes for my 4 foot 240 litres

[simfish]

My 4 foot is like something like the aqua one tanks, i.e. light and filter built into the hood. I have 2 Sun tubes about 900mm. Each tube is 30w, 50Hz, 14000K. I am trying to create a natural aquascape setup. I have undergrqvel heating, CO2, fertilizers etc. However I know my lighting is not correct. MY "K" value is too high and my wattage is too low> I know the ideal "K"value would be around 6500 and the wattage in total should be between 120 to 180 W in total. I am restricted to the tube size and system because all the mechanics com together to fit perfectly. Can I get a single tube which is about 6500k pushing around 60W to 90W bearing in mind tube and fiiting is smaller in dia than a typical flourescent tube you find in your office. Its the width of the ones in a typical petshop, I'd say around 1 inch..... please help as everything else I have sorted but this and it does no seem to be a straight forward thing... :oops: :oops: :oops:

[alanmin4304]

I have a 4ft tank with 2 x 3ft flouros and two 15 watt incandescents which are on all the time to prevent the shock when the flouros come on automatically at 5.30am. At the moment the flouros are on 15 hours/day. Light intensity is one factor but the depth of water is more important in my view. I have a growlux in the front and daylight in the back. Works OK for me. The incandescents are on dimmers but at present are on full strength---looks like moonlight at night. My tank is 6oomm high. The plants have to be pretty well established to get away with 15 hours/day, I have worked up to that.