Be sure it's all the 500ml you are mixing with. If memory serves 60 grams is about the limit so you should be under it, but it still takes a bit of mixing.
My calculator is coming up with 50 grams with 250 ml of water not 500 ml.
Will 250 ml vs. 500 ml put me over the solubility limit?
75 Gallon--Rainbow Fish Tank/Amano Shrimp
29 Gallon--Celestial Pearl Danios/Yellow Shrimp
20 Gallon--Ember Tetras/Orange Shrimp
10 Gallon--Chili Rasboras/Cherry Red Shrimp