I always use silica. Protekt is one brand. Toughens up plants. Makes stems stronger, leaves tougher to resist pests/disease. Also doubles as PH up. Can't hurt plants, even young ones.
Have to agree here if your going to add something mite as well add something beneficial to your plants. Make sure you use a scale for your measurements of maxi it should be 7g/gal. get a digi for it. I add about 5ml/g of pro-tek silicate, I have used the silica blast but it don't adjust ph you still need to use a ph up supplement. add the pro-tek to your water before you add your mixed maxi.