Mixing the spectrums

[Essabee]

Some of you know that I am building a new aquarium for myself, its about 1000 liters and will have plants and pressurised CO2. The water depth shall be about 2 feet.

I have already ordered the lights for the aquarium. Its going to have 5 nos. Metal Halide 150 Watts fixtures and also 4 nos. 36 Watts PLL fluorescent. The tank shall also receive some direct and indirect sunlight from the terrace side where I have a tinted glass hatch opening in the canopy of the tank.

I have always believed that a full spectrum is the best light for an an aquarium - planted or otherwise. A full spectrum will bring out the true colours of whatever the tank contains. When it comes to planted aquarium the spectrum and the intensity of light becomes even more interesting. Now its my hypothesis that if plants are given a flat intense spectrum of all the colour bands used for photosynthesis - each specie of plant will develop its full colouration and you will also be able to see it in all its glory.

The limitation are the bulbs available to us. Each bulb has its limitation in reproduction of the visible spectrum. So I have decided to solve the problem by mixing the spectrum. Past year I started mixing florescent bulbs with different spectrum in my smaller tanks with some success. Then you all know that florescent bulbs are not full spectrum ever and limited to the colours emitted by the specific phosphors in the mix of the coating.

My new tank provides me the opportunity of mixing the spectrum of MH bulbs. Out of the 5 nos. 150 watt bulbs 2 shall be of 10000K and three of 3000K. The 4 36W florescent shall be of 6500K. I expect the final light to look a little yellower than the 6500K MH. Somewhat like golden sunlight.

[Mollielover]

I'd be interested to hear about your results.  I can't wait to see that tank finished Joy.

[Essabee]

I had recieved on Friday evening the bulbs I had ordered. I made some changes in the current 1000L tank - The Incomparable. Out of the 5 150W - MH 3 are now 10000K and 2 are 3000K. Keeping the 5 40W T8 2700K off the tank looks much brighter and the colour looks so natural that unless you open the top and make sure, you would think it is an outdoor tank lighted by natural light. Oh! I just love this combination.

I believe the brightness increased because the intensity of the green-yellow in the resultant spectrum has increased. That's not all, the pink granite that I had used to build the rear and the side walls now looks pink, a colour I could only see when there was direct sunlight in the tank.

I do not want to reduce the wattage of the lights used for this tank or I would be changing the experiment I have taken up. If I light up the 2700K T8 then they will make the present resultant spectrum lopsidedly high in the yellow bands. The type of T8 I now need is something like the Azoo Tri-Power which spikes at the red and blue ends. I think those will be just right. I hope I can find 5 X 48" of those.