Your Macro will out compete your GHA.... I would manually remove as much of your GHA (pulling it out) as you can and make sure your macro is getting more light and of the correct spectrum(3200k-4800k) 6500+ just wont let it thrive.
Keep running gfo to pull the phates out your rock, and do atleast 20% w/c weekly.
The algae fix wont solve your problem it will only patch it.... But if your set on the algae fix the macro will do just fine in the bucket so long as it has heat(room temp works fine 68-72 deg) and a light schedule to keep it from going sexual or dormant... I have cheato growing in a ziplock bag that I got about a month ago, and it is a green as green can be and hasn't seen new water since I put it in there.