The best replacement for silica is silicon.

The best alternatives to silica are rated as following:
★★★★★  silicon
★★  biotin
★★  cotton wick
★★  quartz
★★  silicea
★★  silicate
★★  ekowool
★  horsetail
★  collagen
★  silicon dioxide
★  silicone
★  mesh
★  cotton kayfun
★  crystalline silica
★  alumina
★  asbestos
  biosil
  silicates
  precipitated silica
  hydrated silica
  free silica
  carbon black
  selenium
  mica
  stainless wick
  talc
  vitreous silica
  msm

Your alternative for silica is not listed? Suggest!
Speaking about silica, one probably shouldn't forget about horsetail.

Other search terms related to silica and their ratings are:
★★★★★ horsetail
★★★ msm
★★ biotin
★ titanium dioxide
alumina
You have in mind a companion for silica and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of silica in all years. Click on graph for more.
silica
silicon
biotin