dwc and feeding schedule

hi
im running a 100l rez with RO so ec is 0.0 to start.
im using canna aqua nutes and feeding according to their online feeding schedule.
By doing this i am acheieving the exact e.c's that the chart states i should be getting, however i have recently had cal/mag def's, did some reasearch and found that most people use a cal/mag substitute especially when using ro. My issue is that my e.c will now be well over specified on chart because of adding cal/mag, what should i do to keep the ec specified on chart? reduce a+b nutes, reduce rhizotonic etc? or nothing at all

cheers

I would do 3ml of Cal-mag per gallon im running a 25 gallon res myself but im useing AN!

i know how much to cal mag to put in, i go by bottle guidlines, my problem is that if i feed to canna requirements on their chart and achieve correct ec, they dont specify cal-mag on their charts and havent accounted for it so by adding this aswell i go up to nearly 2.0 ec rather than the 1.4 indicated on their feeding program, cheers tho

Heres what you do... add your R/O water check your PPM/EC ( PPM here in the states) then add your cal/mag check your PPM/EC again for instance after you add your Cal-Mag to your res you get a reading of 300 PPM/EC well dont include that into your final PPM/EC count, subtract your PPM/EC reading with Cal/Mag from your final PPM/EC readings.

With Cal/Mag & R/O = 300 PPM/EC
After you added everything you have a 800 PPM/EC subtract 300 PPM/EC from 800 PPM/EC and 500 PPM/EC is what you should have.
Its that simple, when I started growing I was worried about it too..Happy Growing.

does canna contain calcium and magnesium?

im not sure to be honest but i was showing signs of calcium deficiencies so im guessing not plus the RO strips the water of the calcium already in it, cheers for info anyway, ive fed at full strength according to cannas chart and added the cal mag n all seems good , another quick question for you gurus out there, as you know im feeding with canna nutes, all apart from the BOOST due to the high price!, wondering if anyone knew if it was worth it (pay for itself ) with an increased yield spread over 6 plants providing everything is done correctly?

Matty, Canna sure makes it hard to tell what your feeding your plants. I had to go to a GOV. site to find canna stats.
It lacks several micronutes, and has low calcium and magnesium. If you google canna and mag def you'll find many threads discussing it. Many folks add epsom to remedy this. Shame on cann for not putting their npk's on the fricken label and the web.

you are probably over feeding if you are at full strength plus cal-mag. You can get away with it in veg, but it'll bite you during flower.