Switching to Fox Farm Nutes - will I need Cal/mag & Liquid Karma?

I have a similar question, using Fox Farms GB, TB, & BB trio, per their dose chart or a little bit weaker... small indoor grow, 1k HPS, CO2, and the girls are in approx 7 gallons of ProMix BX.

The chart shows 2 tsp/gl of tiger bloom and 3 tsp/gl of Big Bloom: I mix these up in separate jugs, and feed each on different days. Can I mix the doses into one jug and feed like that? I am not unhappy with doing it separate, and the girls, at flowering week 4, appear pretty happy?

missnu said:

if you don't use distilled or Reverse osmosis water then you don't need Cal-mag...it is already in natural water, tap water, spring water, mineral water, and bottled water...so...

Click to expand...

I know this is an older thread but I had to respond to this comment as someone looking for an answer to whether they should use calmag or not will be misinformed a bit.

It's not just if you use RO or distilled water or not, it is about the PPMs. If you use tap, spring or filtered water that has a PPM lower then 150 or so, you NEED to be using calmag. Even though we do not know what is in that 150 or less PPM exactly, we do know it's not enough cal or mag. I know from experience, and in flower whenever I'd either quit using calmagplus a watering or two, or used less of it then the recommended dosage, I'd begin to have issues in a week or so. I experimented and quit using calmagplus in about week 1-2 of flower in FFOF soil with dolomite and issues got worse, I corrected issues by adding in at least 5ml per gallon of water/fed EVERY watering. Next round I started full strength calmagplus earlier and continued 5ml per gal feds throughout flower until about week 5-6 and issues were far and few.

Although many other factors could of been responsible in my example and for other people's grows, the FACT is if your tap, spring or filtered water is lower then 150 PPM, even maybe 200 or so, you NEED to be using calmag or a similar product. Especially in FFOF soils using FF nutes.