Hi this is my first post. I am upgrading the lighting on my Juwel Reo 240.
I'm converting to the T5 system, but don't know which wavelenghts are best for plant growth. Also which tube should be placed at to front of the tank?
Thanks for taking the trouble to reply.
I've actually bought the lighting unit ( Juwel ) so the tubes must be their own make due to their unique length.
I had seen the photographs in the posts you suggested but they are not Juwel's.
Juwel suggest 2 combinations and I wondered which option to go for.
1) Day 9000 Kelvin + Nature 4100 Kelvin
2) Day 9000 Kelvin + Colour 6800 Kelvin
The dealer offered me 2 off Colour
The plants don't care what bulbs you get. Therefore get whatever colors you like to see. That is the true value of the information in that thread I provided the link for. The kelvin values determine the color tint and the photos James provided give you a hint of what type of color cast the bulbs with similar Kelvin ratings will give. The 9000 is more blue, the 6800-7000 show a greenish/yellowish and the 5000 and below show more orange/red. All have the same value in terms of plant growth so you can mix and match to your own taste.
I also would be surprised you are forced to use only Juwel bulbs. I could be mistaken but I'm sure there are plenty of options for whatever length fixture you have. Have a look at some of the websites and note the tube lengths.
The new Jewel Highlights units are currently some unique sizes, but hopefully some other manufacturers will start making them in those sizes/wattages soon. My Rio 180 needs 45W and 895mm, whereas the only other bulbs I could find that were 895mm long were 39W!
Personally I have a Day at the front and a Nature at the back and the light's nice but maybe a bit greenish (to my colour-blind eyes!). I was tempted to put two Days in with their 9000K colour temperature, but think a mix might be better and I'll stick with what I've got for now. Jewel recommend either Day+Nature or Day+Colour.
I've just returned to fish keeping after a 30 year gap. I was always under the impression that the wavelength was important for the plants. Now I know better. Although when I think about it, in those days I used ordinary tungsten bulbs.
If my memory serves me correctly, I was keeping fish when the grolux tube was made available to aquarists.
Thanks for the help