Just some quick background. I have some California Orange Bud that is about 4 weeks in. It's in a Rockwool Hydro-Drip system and currently under a 400w Sunmaster Cool Deluxe MH light (Lights are 21-inches above tops). For nutrients I'm using the General Hydroponics 3-part system as well as Cal-Mag that is added to distilled water.

Picutres attached are from week 3 and week 4 after they were seeded.

I've been reading all the posts about PPM and I've used the chart Zandor provided for GH. But, I'm still a bit confused. Everyone I talk to and the books that I've read state that you should use 30%-50% of the strength listed on the back of the bottles. Right now I'm using the GH mild formula of 5ml/gal for each (Gro, Micro, Bloom, Cal-Mag). I plan on increasing that to the veg strength of 15ml/g, 10ml/g, 5ml/g (Gro, Mico, Bloom) next week.

Right now my PPM reader is coming in at 280ppm. Everywhere I'm reading says I sould be at around 500-800. But since I'm cutting the bottle amount by 30% of the ppm is much lower.

There doesn't seem to be any problems. It's growing fine, no sign of distress. It's a bit hot in my grow room right now and I'm having problems with that, but nothing that would make me beleive I'm starving them.

Thoughts?
hbbusa28 Reviewed by hbbusa28 on . PPM Levels - after reading; still not sure Just some quick background. I have some California Orange Bud that is about 4 weeks in. It's in a Rockwool Hydro-Drip system and currently under a 400w Sunmaster Cool Deluxe MH light (Lights are 21-inches above tops). For nutrients I'm using the General Hydroponics 3-part system as well as Cal-Mag that is added to distilled water. Picutres attached are from week 3 and week 4 after they were seeded. I've been reading all the posts about PPM and I've used the chart Zandor provided Rating: 5