Looks like hair, fuzz, AND clado.
Once algae is this well established, simply changing the tank setup and parameters usually won't make it go away on its own.
And clado is a special case - it likes the exact same conditions as plants, can't be avoided by changing parameters at all, and is resistant to H2O2 and Excel. Which really
Furthermore, even with one bulb, it's possible you still have sufficient light that some carbon source is required, like from Excel. Or Metricide, which is more expensive up front, but much cheaper in the long run. And of course, it has algicidal properties when overdosed.
I can't comment on the root tabs, but others might be able to; provided you say what kind and how many.
I don't think I've ever suggested sterilizing a tank and starting from scratch, but here I would consider it. It will be one heck of a fight
beating this algae, perhaps more than your finances or patience will allow; though if you do, at least you will learn something in the process. You'll have to correct all your tank parameters, then get rid of the algae through a combination of physical removal, chemical treatments (like my combo treatment
), maybe even AlgaeFix too.