[MatPat]

I would also be very interested in the results of such an experiment.

I wonder if the concept of direct sunlight causing algae is just a myth that has been ingrained in us so we don't doubt it at all anymore :???:

Every book on aquariums sternly tells you to set up aquariums away from direct sunlight... so that's what I've always done. What if it's not really the case? :-s

You never know, it could be a similar "truth" to the one stating that Phosphates cause algae...

This would definitely be an interesting experiment! Aquarium books/online sources also recommend that you use carbon, zeolite, etc, etc to remove ammonia and such from our aquariums. There is also the recommendation to "cycle" the tank before adding fish. Planted folks do neither of the above so maybe you can be the one to prove the myth wrong!

I would, however, use an alternative source of light along with the sunlight for those cloudy days. We've had 4-5 straight days of cloudiness here and that may cause lack of light issues.