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 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?

I'd honestly like to see a little more to that plant by age 4 weeks...You could drop your lighting down as well (although you mentioned heat issues so maybe not) but if that were my munchkin I'd up the nutes. ;)

Just watch for tip burn as you increase the nute strength. A well developed plant will handle the increase easily. When you do see burn, record the EC/ppm- that's as far as you can go with that mix. Back off maybe 10%.

When you move to the bloom mix, do the same thing. W/ the GH, I'd run it pretty high into week 5-6 of flower and then start cutting back hard.

Rhizome....could you define "cutting back hard" ? I'd like to try that one the grow I'm doing now....white rhino....then when do you flush?

Are you running the GH program or the Lucas variant?

Additives?

Rhizome...could you check your reps?

Joe I'm definitely leaning towards letting her do her thing.....she's gotta be free...she's gotta be herself....how does that song go? :)

Shoot....wrong answer for the wrong person.....now I have to go find joe...sorry hb 28......:(

that is really small for 4 weeks mine was 1 ft tall by then im using advance nutes though

Thanks guys. It's been just over 3 weeks since sprout and it's 5" tall. Not 1 foot by anymeans though. I'll up the nutes see what happens.

Also, I read the nute and additive post by Latewood. Sounds like that Liquid Karma is a great addition to the GH 3part nutes I'm using now. I'm going to go out today to see if that helps out. When I add that in should I be using 30%-50% strength of what it says on the bottle like the GH nutes?