I usually put the silica in the water first then wait 15 to 20 mins to mix in well with water. I did not do this a long time ago and I had s fall out reaction and it screwed my plants up and they ended up like this. I always shine a flashlight when mixing to watch for this( i mix in a black bucket dwc makes it hard to see if mixing well. You can see the fallout happen if you mix wrong.