Go slow when starting RDWC it is very different in the ability of the roots to uptake food. I run at 1/2 what they recommend for DWC. The R makes a big difference and add to that water running at 61/64 degrees they respond to any changes very fast, in some cases hours. If you check out my current grow I always post pics of my meter readings. I use the following DM products
Gold Flower A&B 40% recommended
ADD.27 Flower 40% recommended
Silica, go easy on this I use 25% of recommended!!
Zone 50% recommended (when I start I put 100% recommended and run for 3 days before putting the plants in.)
Liquid Light
Gold Saturator
Maji-cal or Cal-max 25% recommended
I build from there to get my target PPM and Ph.
#1 rule!!!!!
Don't chase PH, pick a range and stick to it. I use 5.4 to 6.0 if it changes I just top load to get it back. When you have it dialed in you PH and PPM will tell you what to do.
Here is a handy rule of thumb
If your nutes are at 500ppm and two days later there at 350ppm you need to up your ppm! It works like this, change res set ppm at say 600ppm ph 5.9 run for 24hrs, now if you ppm rise and ph drops nutes are too strong. If ppm drops and ph rises, nutes are to weak. But if your ppm and ph are basically stable then you have found the right mix for your plants.
[FONT="] Then when topping off your res use pre mixed nutes to keep it at that level, if it starts to rise or fall adjust top off nutes as needed to bring it back to proper level. This is how I run my system and has worked great for me!
[/FONT]
[FONT="]
[/FONT]
The only none DM I have is Big Budd and have yet to use it.