It depends on your medium. If it has any starter ferts in it, wait for the first set.
If it's soillless (Promix, Coco, Peat, etc) then start from day 1 at 1g/gal. On day 6, bump it to 2g/gal. Then bump it 1g/gal every week from there, give or take. Keep 'em in the verdant zone.
I soak my rapid rooters in 1g/gal even. If the medium is basically inert, it needs a tick of food from the start.
Add nutes to the new water when you change your res. Your top off water between changes shouldn't be full strength. Keep track of your starting EC/TDS/PPM, whichever you're comfortable with, and then know how much MC/gallon you need to add to top it back up.
It's no different than any other nutrient line in terms of when to use it.
If you're week 4 of flower, you would normally be at 6g/gal of MC. Since your other feed is a bit light for where you're at, I'd go with the above suggestion to do the first feed at 5g/gal, then the next one at 6g/gal.You probably what, about 2 days between feeds at this point?
Are these photos or autos? If photos, 5gal pots are a little small for Promix. Using 7 or even 10 for a photo would serve you better. I'm running an auto blue dream right now, and she's in a 7gal fabric pot with promix.
If you're using calmag as well, it would help to know what the NPK ratios are. I use CALiMAGic (which is 1-0-0) and it's cal % is like 5%+/- which is good for the amount of N. You have to watch your N-K ratio, and not exceed 1:3. MC on its own is just under 1:2 IIRC off the top of my head at 9:17 for N:K.
That being the case, in ProMix, this has been my entire feed mix (all credit for the mix to
@farside05) :
Products:
- Pro-TeKt (DynaGro)
- CALiMAGic (Gen Hydro)
- MegaCrop
The formula is always the same per gallon.
1ml ProTeKt
1ml CALiMAGic
1g MegaCrop
Need 4g/gal MC? Use 4ml ProTeKt, 4ml CALiMAGic, 4g MegaCrop.
5g/gal? 5ml/5ml/5g.
Here is
@farside05's schedule. I've been following it to the letter in promix:
One of his many posts in this thread about it:
Giving MC a shot, subbed I grew your Bedroom Cookies with it this summer in ProMix HP!
www.420magazine.com