I'm planning on mounting the 2x24w retrofit kit in an All-Glass 30" Black Pine canopy.
The tank is only 12" tall, but it is 30" long. They bulbs are 24" and they can be mounted in a staggered/offset way that the ends only get 24w of lighting and the center most region gets the full 48w or 2.4 wpg.
I could also center mount both T5 bulbs and have a pair of spiral 23w 6500K bulbs mounted at each end or I could use the Coralife 10w or 20w Colormax freshwater screw in CF bulbs. I've also seen some 6500K or 6700K 27w quad PC bulbs too.
I also have a spare AHSupply 36w/55w retrofit kit. I have a 36w 6700K bulb and a 55w 9325K bulb for it. I just need to get the 55w reflector from AHSupply. It'll have to be mounted in the centered back portion and only used for a noon burst effect for 1 to 2 hours or so, I believe.
Is a 2x24w HO T5 light retrofit kit good enough or do I need just a touch more?
These plants are new to me. I just purchased the HC and Glosso to get it growing right away. I don't have the Rotala macrandra yet
If the 2x24w kit won't work; I have a new 30" 2x65w Orbit fixture with a 65w Colormax/6700K bulb and a dual daylight 6700K/10,000K bulb. I know it will work. It'll be 6.5 wpg if I run both bulbs or 3.25 wpg if I only run one. The bulbs in this fixture are centered.
With the individual reflectors, I'm pretty certain the T5 set would work quite well, especially on a tank only 12" tall. Have you priced a retrofit kit based on the IceCap T5 reflectors which are better than either the Tek1 and Tek2 reflectors? If it's not too much more, I'd go for the IceCaps. Otherwise, the Tek2 will do a good job.
Why not use the 30" fixture from the start? You'll get more even light coverage...and more light. Or are you planning to return it or are you afraid of such high light levels? A constant 3WPG is quite a bit of light and you'll have to stay on top of dosing and CO2.