Drop light intensity by about 35 percent and reduce the duration to 8 hours max. Use 30 minute ramp up and down. Improve flow throughout the tank and try to get tank turnover to around 5x to 10x water volume per hour without blasting the fish. Discontinue root tabs, continue dosing easy green per directions. Start 30 or 40 percent water changes daily but dose the the incoming water volume with easy green. Example, if you change out 20 gallons, dose easy green for 20 gallons. You want the all NO3 to come from fertilizer, not from the tank. Clean filters, lightly gravel vacuum, just clean the surface, don't jam it down in the substrate. Target an over tank of 20ish ppm NO3.
KH is high and I would research how to slowly lower it some. GH can be boosted with readily available products. Just do some reading. Ignore pH completely, it means nothing.
This is where I'd start.
If a substrate swap is soon. Just water change for now. The tank will reset after and algae phase will restart.