Grow Mediums How long before you start adding nutes?

[Autotron]

@Autotron, it's true the plant has enough nutes for a week or so, but I NEVER wait to test that theory.

The plant may have enough to survive in its embryonic stage, but nutes in the mixture do encourage faster root growth. ​

Go ahead with a general purpose mild formula of 1/4 tsp. per gallon grow, micro, bloom, diamond nectar, FloraBlend and 1mL Floralicious Plus. You can "mix-up" this strength by adding extra parts of each nutrient as the plant progresses. After one week I want 1/2tsp of each, so just add another 1/4 tsp. per gallon.
I like to start my seedlings in a little Folgers coffee can bubbler inside a 2" net pot until I get three nodes, and a good long root growth. Since you've started your girl directly in your DWC, be sure to raise the water level in your DWC container high enough to keep the rapid rooter plug moistened. You can go all the way up to the bottom of the rooter plug if you like. As soon as the roots hit water they will take off.
Tap water - are you in a part of the country with hard water? If so, do you have a water softener in your water supply line?
Root supplements - one day soon I intend to get to the bottom of this for hydro. No question whatsoever that myco's etc. are a good idea for dirt farmers. And many / most (myself included) use them in hydro. I'm not willing to quit just to see if it fucks up my roots, but I am curious what real effect it has in hydro. In order for mycorrhizae to inoculate your roots, they have to maintain direct contact with root matter. I am curious how this works in a hydro environment. Soon as I find a microscope slide of what this looks like I intend to do a bit more research on the subject. But that's a fall / winter project. In the meantime if you have root innoculants mos'def' use them, guaranteed it doesn't hurt.

Just realized I didn't really answer your question about the hardness of my water. I looked it up and apparently my tap water is classified as "moderately hard", between 5.5 and 7.5 grains per gallon of Total Hardness(100-125 milligrams per liter which is the same as PPM). The amount of calcium in my water is anywhere between 24-34 PPM. GH says to use their hard water Micro only if your calcium hardness is above 70 PPM, so I'm well within the safe zone(https://generalhydroponics.com/water/). Also, I do not use a water softener and no one on municipal water does as far as I know. Interesting how much I learned today by looking this up!

 

[Olde School Player]

I hear you bro, I was itching to get some nutes in there, even a diluted brew. I'll add Floralicious to my next water change in a couple days. I'm basically using exactly what you mention for first week too, except for that.

I did start it directly in the 5 gallon bucket, but there is a submersible pump at the bottom of the bucket that circulates a gentle stream of water back up onto the base of the Rapid Rooter to support root growth until it gets big and established enough.

My tap water has a PPM of about 130-140, so it's not too hard. It's considered quite good quality municipal water as far as I understand.

The only root supplements I'm using is GH Rapid Start and Botanicare Hydroguard. I feel the same way as you. I don't think mycos like Great White or Recharge have any place in a hydroponic system.

Been away for a few days, sidetracked getting my RO system rebuilt & getting ready for my next grow. And with a little break in the forum action I'm trying to keep up with where I said what.... There were conversations, here I believe, about a newly sprouted plant's ability to live for 1-2 weeks without nutes. That's absolutely true, you can do that, but it's also absolutely going to hurt development of your seedling - roots as well as overall development. So as soon as you get a good root start, at about the time the seedling has grown to three true nodes, then you can step up the nutes to around 500 - 600 ppm's. Lots of people worry that autoflowers aren't as nute-tolerant as photoperiods, but 600ppm is not going to hurt a thing.

I'm getting ready to start a new thread with a Dinafem Blue Cheese Auto that I germinated ten days ago. In that time she's already set roots a foot long and is looking like a reaol plant with secondary branches showing at the 1st and 2nd nodes. Soon as she goes under the "big light" I'm starting here at 650ppm's. I'll be posting some pic's & will tag you in so you can see what I'm talking about. Transplant- wise I'm behind you but I think you can follow my regimens & catch up with plant growth.

I see in your main thread that you've also had conversations with BigSm0 about light height. He and I have a friendly disagreement going about that topic - I'm of the firm conviction that stronger lighting helps a plant's development during its entire growth, and greatly improves yields. He sells his 55W COB's as a 150W HPS and LED replacement. No arguments that he has an excellent product & those figures are pretty good. I bought two of his COB's and I'm looking forward to trying them out this Fall. But that amount of lighting is not going to burn your plant if you lower them.
So there's two things to watch for to see if your plant can handle more lighting. The first is if the seedling is stretching toward the light & becoming weak & spindly. That's a sure sign to lower the light. Some say start high and let the plant grow to the light. I'm of the opposite conviction - start at 30" with a new seedling but lower it daily so that in one week you're about 18" above the plant. Second thing - the amount of nutes a plant can tolerate is directly proportional to light intensity. Put simply, lower density lighting (less ppfd, lumens, watts, whatever measure) requires lower strength nutes. Or more importantly, the inverse, stronger lighting will allow your plant to use stronger nutes.
So, if you grow with one autoCOB, you probably won't be able to run higher nute strength. That's OK, you can still get good results. But if you watch ppm's closely, and adjust your ppm's upward, you should be able to increase yields by a significant amount. With my single plant grows, I'm disappointed with anything under 6oz., mildly satisfied at 8oz., but I really don't start smiling until I see 10+oz. yield. But that's with 250W HID lighting that has transitioned to 325W LED lighting in a 5 sq.ft. tent.

OK, more forum catch-up to do. I'll be watching for some updated pic's in your main grow thread, and soon as I get my new thread started I'll be inviting you along for the ride.

 

[Olde School Player]

Just realized I didn't really answer your question about the hardness of my water. I looked it up and apparently my tap water is classified as "moderately hard", between 5.5 and 7.5 grains per gallon of Total Hardness(100-125 milligrams per liter which is the same as PPM). The amount of calcium in my water is anywhere between 24-34 PPM. GH says to use their hard water Micro only if your calcium hardness is above 70 PPM, so I'm well within the safe zone(https://generalhydroponics.com/water/). Also, I do not use a water softener and no one on municipal water does as far as I know. Interesting how much I learned today by looking this up!

Looked back at the beginning of this post where you said your water is 130-140ppm, that's pretty soft. My well water runs 380-390ppm; most of which is calcium & magnesium, but I do have a softener so I have to run RO and add back cal-mag. So by the time I add 4mL / gal. of cal-mag and another 2mL of ArmorSi (silicates), my base RO is at 350ppm. So if you take that into account, what I said earlier about 600ppm is not that far "out there".
But what that may mean for you is that you don't have ENOUGH calcium & magnesium in your water. In fact, at 100-125, I can practically guarantee you won't. Even at 4mL / gal. cal-mag, I sometimes see mild deficiency when into early / mid bloom. This next grow I'm up-ing my formula to 5mL / gal., and leaving Si at 2mL / gal. Thatr' going to up my base water ppm's but I'll keep that in mind as I check nute strength.
DON'T RUN GH's hardwater micro. I never had good luck with that even before I went to RO.