Algae and plants dying
A quick overiew... I have a 20 gallon high tank that is fully cycled and is stocked with corys, tetras and apistogrammas. I recently changed the substrate to sand (from course gravel) and am trying to go the planted route. Currently there are java ferns, anubias, a small and a large amazon sword, ludwigia repens (that is still surviving but not thriving), a couple of crypts and dwarf water lettuce.
I have recently had issues with algae growing (I think it's BBA since it was growing in furry clumps and was also settling on marimo moss balls) as well as plants that aren't thriving.
Fertilization: I am dosing Thrive as per bottle instructions three times a week and have placed root tabs under all of the plants in the sand. I use seachem excel daily as a carbon source and algae control.
Lighting: Beamswork DA 6500K set to a timer (was 8 hours but lowered to 6 hours and am dimming the light to about 70%)
Filteration: Aquaclear 50 and I am adding a powerhead to increase flow around the tank to help keep detritus from building up.
I guess my question is really just to ask for any opinions or advice on my current set up. I have only recently ( within the past two weeks) started dosing thrive and excel. Should I just be waiting to let the dust settle? I have been doing water changes more often (twice in the past few days) and also trimming and pulling dead plants.
Other than lowering the amount of light, is there anything else I should be doing with this tank?