Hi. New to the board.

I have a quick question about the kelvin rating required for aquatic plants. I have an overtank T5 unit (4 tubes of 30w each), which until recently was used for my marine setup. Due to funds, time available and various other things i had to strip it down, and i'm now using it on my colwater setup (i haven't yet branched out into live plants).

The tubes themselves are 14,000k and practically brand new. So my question is, would they be suitable to use for live plants, or is the kelvin rating too high up the spectrum?

I don't have much knowledge of aquarium plants, i'm used to dealing with corals.

Thanks in advance!

That sort of K is meant to simulate tropical sunlight penetrating several metres depth, where the blue penetrates deeper.

Freshwater plants live more shallow (less than a metre depth) than corals and so require more red, so 6500K tubes are more preferable to the bluer 10000 or 14000K tubes.

More ideal would be to use Sylvania Grolux tubes, which is a non K-rated plant-spectrum tube now available in T5, and what I use myself.

PS. I have a set of brand new actinic and 14000K T5 tubes myself as they came packaged with the light fixture. Waste of money having to swap them out!

Cheers, awrieger.

I can't say i've heard of Gro-Lux before, but i'll check them out.

Can any of the hardier plant species make use of 14, 000k lighting? Such as java fern or anacharis? I plan to start out very simply anyway, so if i can make use of these tubes it would help greatly until i come to renew them

You can if you want to. 10000K are often used by people who prefer the cooler blue look and think the 6500K is too green/yellow. Yet other people prefer the exact opposite. So it's really a matter of personal taste. I personally don't think either looks natural at all.

None of them are specific plant light tubes anyway. And they're much brighter to the human eye than a plant tube. Honestly, plants can grow in any type of light, but they thrive much better with light in the red spectrum around 650nm, whereas most non-plant lights are mostly down in the blue 420nm area.

PS. I was actually incorrect about 6500K tubes having more red. I just compared one of my compact fluoro 6500 spectrum to a 10000K and the only difference being the higher the K, the more blue the light is. There's very little red in either anyway. The only reason the 6500K looks more green/yellow is because there's less blue overall, so you see the green more.

PPS. There's a good aquarium plant forum plantedtank.net which has a subforum specifically just for lights. You can search for 14000K there to see if anyone has had success using them and learn more than I could ever tell you.

I'm not particularly bothered about the asthetics, more the benefit (or the detriment) of higher kelvin ratings to the growth of plants I wasn't quite sure what affect it would have on their quality, but thanks for clearing this up

The site looks useful. I shall have a look through it and see what i can find out about the expeiences of others.

I'd like to get as much info. gathered on plants and their requirements as possible before diving in, as i'm sure you'll agree research is key Thanks for pushing me in the right direction, it's much appreciated.