Tim, that ratio is better if you can control your N... 1-2ppm P, 10-20ppm N, 20-40ppm K.
I think that 80ppm K (while not necessarily dangerous) would be overkill. Your plants are not going to use it that quickly. I also think 4ppm P starts to get dangerous for your fish. In your situation with the inherent high N, I would just shoot for 2ppm P and 20-40ppm K.
And yes, NamelessP, those ribbon plants are non-aquatic. They won't survive long term in your tank submerged. Eventually they will start to rot from the base up, and could potentially cause ammonia/nitrite spikes in your tank.