Ive made an observation that Id like to share with you, and see what you think.

I have 2 different types of tubes over my tank at the moment, Hagen Life-Glo (6500K), and Hagen Aqua-Glo (18,000K).

I did an experiment over 48 hours each to observe how much pearling I could see depending on which combo of tube I was running.

My first setup was 2 Life-Glo tubes, running at the same time, for the same period.
At the end of the photoperiod it was really hard to spot any pearling, except for a bit on my surface Riccia.

The second set-up was 1 Life-Glo, and 1 Aqua-Glo for the same periods.
This time, pearling was considerably more on most of the plants, even the Java ferns.

Hagen do state the Aqua-Glo as a pro-photosynthesis tube, and I guess that all I've done is really confirm that.

My trouble is, is that prolonged use of the Aqua-Glo, spurs my brown algae problem into overdrive, and also I get the horrid signs of early cyanobacteria back again. Ive had an issue with unstable CO2 which is now sorted, hopefully.. so maybe thats the cause of the algae in the first place. Id really like to be able to run the Aqua-Glo full time, at the moment though it just doesnt seem possible.