I see a bunch of people have viewed but none have answered here you go!
Firstly what size grain are you looking at for silica sand, althought it's not a big deal I would use a middle of line grain size I believe it's 7 but I would do research on that.
I'm curious why silica sand? Personally I've used and will continue to use normal Playsand for all my planted aquariums, I buy a 60lbs bag @ Home Depot for 5.99$ Any fine sand substrate is okay to use with plants. There are a few problems or better terms obsticles you will have to overcome.
1. Ferts - As you prob know Sand doesn't have any nutrients in it, This is where your fert schedule comes in whether your using EI, PPS-Pro, or just dosing Excel or Flourish either or. All plants will get enough nutrients from the WC if you want your Root feeders ex. Swords, Vals, Crypts, Lotus to thrive I would suggest a Root tabs for them.
2. Cloudy Water - When you first put your Silica or Sand make sure you add water slowly it will decrease the cloudiness in the water from the sand. Also before you even add sand make sure you rinse it off acouple times depending on the sand and grain size. Personally the Target Playsand doesn't need to be rinsed it's not dusty but I still recommend it. When you add the water pour it into a bowl placed on the substrate or plate or something to disperse the agitation into the sand.
3. Rooting/Planting - It will take a month or so for your plants to become rooted into the substrate especially smaller plants. If you have bigger fish - Plecos in general if they whip around the tank sometimes they uproot them so you might find yourself having to replant daily.
Anyways I hope this helps you out, and sorry if i'm repeating already known knowledge.
Goodluck. ---- Also if you have any questions you can direct them through PM.