That's a fantastic web site with some of the best information about RDWC that I've read. I was specifically looking for information on silica when I found it. I've read about everything on the site twice and took lots of notes. I wasn't using silica properly by adding it straight to my epi. Plus I wasn't using it all the time. My current grow is the first using this method. Plants are 12 days flowering and doing great. It's a strain I haven't grown before so can't compare, but I've got some Blue Dream started that I didn't use silica on the last time.
The only other thing I use is bleach as my sterilizer. Again, I got the information from that site. I've got a Hanna free chlorine meter so I tested until I got the right amount of bleach. I mix a solution of 1/2 ml Clorox to 32 oz. RO. I add that solution to the system at the rate of 2 ml per gallon. That give me a reading of .03 -.04 ppm of hypochlorous acid, which is the by product of mixing bleach with water. Hypochlorous acid is the active ingredient in UC Roots. The UC Roots I tested yielded .03 ppm of hypochlorous acid. Up to .05 is fine. It dissipates over about 3 days so I add it every 4 days. Roots look great.
I'm still learning how to properly handle my nutes. I was going through my grow notes yesterday, looking at the numbers I was running. Everything was way too high and I see now why I was having some of the problems I did. I was trying to follow the H&G nute guide too closely and not diagnosing and correcting quickly enough. H&G techs were great help. What I'm doing now, starting at a system change, is set my nute level based on how the plants have been feeding. If they are feeding strong I up the ppm by 50 (500 scale) from where it was in the old solution. So if they were feeding good at 250 I up it to 300. If my ppm readings have been flat I keep the same level or drop it a little. I run a top off res that I set to the same ppm of the system. Over the course of the 18 days it all depends on what they need. My current plants are dropping about 7-8 ppm a day, so I'm supplementing every 5-6 days. Not to say this is the best way to do it, but it's working good for me as I continue to learn.
