Sanity-Check my nutrient recipe.

I'm growing several strains including a pure sativa (20 week flower) and a handful of I/S and S/I hybrids. I grow in coco coir + perlite in 18-22 gallon bins lit by 2x 400W HPS and a few hundred watts of florescent. Now that I'm hitting my stride I want to take it to the next level. I just picked up some Botanicare Sweet Raw and some Canna PK 13/14 (week 7 only). Now I need to alter my recipe.

Strains are: Blue dream, Sweet-n-Sour Diesel, 707-Headband, Jacks-Old-Time-Haze.



My nute recipe has been (per gallon) 25ml PBPG, 25ml PGPB, 10ml cal-mag. I've been instructed to change it to 20ml PBPG, 20ml PBPB, 10ml cal-mag, 10ml Sweet Raw, 6ml PK-13/14 (the recommendation of one of my many mentors).

Thoughts?

My lights are an easy 18" above the plants but don't run cool-tubes or any of that jazz.

Should I use the PK spike only suddenly in week 7 as instructed or (as I've seen done by others) add a little (3ml/gal) from week 2-6 and then in week 7 spike it with the full 6, then let the flush happen the remaining 2-3 weeks.

Yes, I have mentors and I still ask. Why? You want 7 "perfect" and diametrically opposed positions, ask 3 growers.

Shit, 79 views and not one of you has a suggestion?

what up
I used atami (b'cuzz 13/14),which is pretty damn close to the same product. I used it at 75% of the rec dose weeks 1 through 4. Then used it full strength 4 through 7. then flushed for 10 days. chopped them down a little after 8 weeks in flower. Considering that P AND k ARE 2 OUT OF THE 3 MOST USED NUTES, I say lay it on as heavy as the girls can take it.

what kind of early signs of toxicity/over-application am I looking for.

Also, I see a lot of brave souls have decided to hit them with the modest doses throughout the flowering with the full hits in week 4 and thereabouts. What's up with that? I can't imagine why the manufacturer specifies just week 4 when it seems like it can and often should be used during the whole cycle, just carefully.

Have you experimented at all with lowering the doses or deleting it at particular times and the resultant effect on production or did you arrive at that fairly heavy application by the "it's not killin' em'" technique?

For now I'm using a 1ml/gal PK hit for general flowering and on my week 4 set I've bumped it to 6ml/gal. I'll back that down to 1ml/gal till harvest and then the 20 week plant in there will get another 6ml/gal spike for another week and back down to 1ml/gal. I'm experimenting now anyway... thankfully I've got a nice supply of clone stock for the SnS diesel strain that I'm focusing on. Next round I'll play with it a little more.

I'm running CO2 now too so I may have to up my nute supply to support the mass gain.

Well, barring any useful advice from those that are supposed to be the ones we turn to, I've verified my recipe myself. The following doesn't burn the sativas and it doesn't starve the indicas. This is for coco coir + perlite medium. Feedings are every 3 days, water to waste.

Veg: Pure Blend Pro-Grow 20ml/gal, Cal-Mag 10ml/gal (bump to 15 if purple fan leaf stems show up)

Bloom:
Pure Blend Pro-Gro 25ml/gal (week 1-3), 20ml/gal (week 4-7)
Pure Blend Pro-Bloom 25ml/gal, 20ml/gal (week 4-7)
Cal-Mag 15ml/gal (week 1-7)
Sweet Raw 10ml/gal (week 2-4), 12ml/gal (week 5), 15ml/gal (week 6,7)
PK 13/14 1ml/gal (week 2), 4ml/gal (week 3), 6ml/gal (week 4-7)

CO2 3cu/ft per day.