is it a good idea to add silica to my top off res?

[IIVIIetal]

hey everyone, ive looked around and cant seem to find a pertinent thread to answer my questioin. I have a 55gal drum that i run airstones and a circulation pump in, that i use for topping up my fertigation reservoires with (running ebb and flow). its it ok to add silica to the fresh water res at normal strength, and then use that water to top off my other res'..... or could that cause nutrient lock out or other issues? ide be using green planets plant guard

thanks for any input or help, have a great weekend!