Here's what I made...

[Undawada]

Thanks to the expertise of Discomafia, I now am the proud owner of 4 x 20 W 6700K lights for my 24 gallon tank.

Few Q's for lighting experts :

The 6700K lights seem a bit dim and yellow, though. This colour range is supposed to be good for plants, right?

Is 4 x 20W actually 80W, or is some light lost due to redundancy?

Would it be smart to mix a few different colour temperatures for the benefit of the plants?

 

[Jer-]

I thought 6700K was supposed to be WHITE WHITE WHITE??!!!

 

[Undawada]

Me too... I was sort of surprised when I plugged it in and it looked dingy and yellow. I used to have a single 18,000 K 20W bulb, perhaps I'm used to the blue tinge it had.

The colour looks more natural, though... it may grow on me

edit: I typed 6700 K, the colour temp is actually 6500 K

 

[Jer-]

Im not a lighting expert but i thought i will jus share my opinion: hope u dont mind. haha

6500K is great for plants, i myself use only 6000K bulbs and my plants are doin Great. I dunno why u would say that the light is yellowy, cos mine are pretty white.

Light intensity will greatly decrease in water, but as long as ur tank is not too deep i think it shud be ok. seeing that ur tank is 24gal and the watts of lighting ur using for it, u are getting more than 2WPG, which IMO is great. I am currently using more than 3 WPG of lighting over my tank. Oh and i have also read that the 2WPG rule only works with tanks over 30Gal. but because u have more than 2WPG it shud be fine.

Mixing different bulbs with different K ratings is ok, as long as the plants can utilise the K rating the bulbs u are using provide. I dunno whether different plants have a specific Kelvin rating that they prefer?? But IMO, as long as the lights u r using or gonna use fall in the K range of 5000 to 6700K (also discomafias advice)everything shud be gooood.

 

[Discomafia]

Would it be smart to mix a few different colour temperatures for the benefit of the plants?

That'd always be a good idea... I know gf225 uses a few different types of bulbs. There should be a thread somewhere where he specifies what he uses. Since we all know the best kelvin range for growing plants is 5000-6700K, I should think that using bulbs with a higher K rating would be best, especially if you want that white tinge, which I do.

That is why I wanted to use a 10,000K bulb, but couldn't find one that was of the correct length. As of now, I only have 1.8 wpg of 6700K, but I plan on getting an AquaGlo which is 18000K, or a PowerGlo, which has the same kelvin rating, but has slightly more lumens. I have seen many tanks on the AGA's contest website that uses just 10,000K bulbs or in combination with 6700K daylight bulbs, and the plants are going great. Good enough for it to be entered in AGA's 2004 contest I should say.

However, I know that gf225 uses a 3000K bulb, so I should think that using that kind of bulb would work as well, just as long as you have the intensity, your plants should be OK. But the light it produces would be a yellow one, so that's why I recommend using a 10,000 bulb or higher.

Also, did you adjust the level of the lights yet, as we discussed? We placed the hinges 1 cm high, try adjusting it to 2 or 3". That and covering the back of your hood, would greatly increase the amount of light entering your tank, and not get reflected away... You said you planned on using reflectors or painting the inside of the tank, that should be better still. Good luck, there's great potential in that tank of yours!