10,000k or 6,500k lights for aquarium plants?

Freshwater plants expect light similar to normal sunlight, which is around 6,500K., so that's what you should be using.

As for the amount of light, what you have is a low level for a planted tank that size. Maybe 2X that level? Punkin's suggestion of mixing 10,000K and 6,500K is sensible, and does look good.

To bring it into perspective. Look at a beam of sunlight shining through the window. See how bright it is, compared to the normal level of light in the room? The plants are expecting light more like that sunbeam.

You may be able to compensate by running the lower power lamps for longer, as long as they are the correct spectrum.

But light is the most important thing for a planted tank. If you don't get that right (amount and spectrum) then nothing else you do is going to help.

Ian

your problem is not the spectrum, you just don't have enough bulbs/intensity. A mix of bulbs including 1 of the 10k bulbs is fine for live plants and will produce the best visual appearance; 6500 bulbs are kinda yellowish and the 10k will produce a brighter white which is more pleasing and is also fine (when used with the other spectrum bulbs) for the plants.

You could double the lights and still be considered a medium to low light tank. But your plants will definitely do better.

The Key is balance, the more light, the more co2 is required. I just started a planted tank, I have a 10k bulb and a 6700 bulb on my coralife fixture, but growth wasn't good. I fixed my substrate (added dirt) and started adding pressurized co2 and fertilizers once a month and now my tank is good! You listed both high light and low light plants, so you need perfect balance so that algae don't take over your tank. This video should help: https://www.youtube.com/watch?v=1SmQ0dQvNCo

Also check out my channel for other fish tank questions: https://www.youtube.com/channel/UCijpuBRpFdKmnZQI4...

I don't understand why there is so much obsession with bulb rating. Like Punkin Eater said, it's what kind of light is out putted by the bulb.

http://www.aquaticplantcentral.com/forumapc/lighti...