The good news, the CO2 is now good.
The species of algae here is not that bad to get rid of.
Trim etc and it'll go away.

Patience is also very much in order here.
You'll need to wait till the new growth comes back in.
You just set up the CO2.nutrients to the good ranges, but now will have to wait for the plants to respond after being starved for a long period.
They will bounce back, I'd suggest some cheapy plants in the meantime.

You also likely did some moving of the plants around recently and did niot follw with a large water change.

Large water changes are no good for algae.
Why? They do two things, add CO2/remove DOC and remove NH4 sources and NH4 itself. Those two parameters, NH4/CO2 are tightly linked to algae.

So keep adding the CO3, no need to gas any fish, look at the plants, but look at a healthy plant, which at this point, do not invclude any of your plants just yet.
A sickly plant is a poor indicator for changes to the tank in any short time frame.

Algae also like CO2 as much as any plant.
So here's what I'd suggest you do:

Clean tank again, filter cleaning, 60-70% water change, add fertilizers back again(normal EI dosing), turn off CO2 and lights, add more current, cover tank with 2 layers of black trash bags so no light gets in, add 8 mls per 10 gal of water of Excel. Next day, do the same water changes, no ferts this time, add Excel again. Repeat this again. Total of 3 days blackout daily water changes(50-60% or so) with Excel dosing at 1.5x the suggested amounts.

Take note, this will beat the heck out most any algae.
Now, add the good level of CO2 back, and add the fertilizers back.
Stay on top of things, add new cheapy plants till these grow in well.
Phase these out as the other plants grow in well.

Resist the urge to pick algae from HC!!!This will look bad.
Allow the HC to overtake the algae and smother it, or, cut the entire section of HC out, a replant using cleaned stems about 1" long and push into the substrate about 3/4th of the way down.

I've used this method on serious algae issues and had excellent results.
But such labor is wasted if you do not stay on tyop of things thereafter and have some healthy plants to start with.

Regards,
Tom Barr