I did the same, topped up a small amount of amazonia powder into my 13gal tank so that I would have slightly more slope. The amount I put in was rather small, less than 100ml worth.
I had a massive green water attack that would not go away even after 2-3 60% water changes per week for a month. I stopped all dosing (and plants STILL grew like mad) in this time period and still the green water wouldn't go away.
Finally after 6 weeks and a weekend worth of UV treatment later, I finally have clear water again.
This is really a horrible experience with ADA and I'll never use this substrate again. I've never had such problems when topping up soil of another brand that provides equivalent plant growth as ADA.