IT LOOKS HAPPY IN THAT SPOT. NICE JOB
So to sum it up you moved them to a lower and darker area? With less flow? I'm having the exact same issue with mine at the moment. Yours look amazing by the way. Well done!
I STARTED USING RO/DI WATER FROM A REPUTABLE SUPPLIER AND THAT MADE ALL THE DIFFERENCE. ALWAYS TEST THE WATER YOU BUY FROM A LFS. THEY ARE NOT ALWAYS SELLING THE BEST WATER. ALSO DID WATER CHANGES ONCE A WEEK FOR AT LEAST 2 MONTHS.how did you get your algae under control?