Newbie Taproot in Rockwool Question, General Hello, Friendly advice invited!!

Hello people,

First of all hi how are you? Hope your all great! It's friday as I write this so finally got my feet up. I'm new, both to the forum and this wonderful hobbie of growing. My seedlings are barely 2" high and I'm having more fun than I've had in ages!! I have done my homework and have decided to jump in at what I would gather is a moderate difficulty level. I think I have a handle on things (maybe that's arrogance) but I guess that will be shown during the course of the next few months.

Basically my question to you is about taproots and rockwool. I have 6 seedlings at the moment in small rockwool cubes 36mm x 36mm x 40mm, I am going to transfer them into bigger cubes and finally into my NFT trays. Yes I have decided to go hydro right off the bat. Maybe a controversial choice please no negativity on this one if you think I have made the wrong move then just give me suggestions to make sure things go right!

Anyway I wasn't expecting such growth from the tap root so quickly and 2 are already poking out. I am currently trying to warm some ph balanced water to room temperature, whilst soaking the cubes at the same time. Don't worry the water is 17p a bottle everyday value tesco nothing but H20 which i thought seeing as it lacks chlorine and even the minerals or metals that you find in mineral water (or so I'm led to believe) then it would be perfect. It means I don't have to wait for the chlorine to evaporate but I am having to wait for it warm up.

My question then (and finally I bet you are all thinking) is will this wait be detrimental to my seedlings that have already poked their taproot out the bottom? I know the shock of cold water would be horrible for them but what about the root not be able to grow or will this facilitate the other smaller roots to spread out. Any advice pertaining to this would be greatly appreciated!

Also just wanted to say I've been reading on here for awhile before going ahead and this site is such a great wonderful fountain of knowledge. Cheers for the help you have unknowingly gave me so far

Oh and thanks in advance on this one folks

PS: Sorry if this has been asked before. I did try to find an answer before asking

Hey Whatisnow,

I also started off with hydro. If you're scientifically inclined and like to measure and calculate, you should be fine. That to me seemed more dependable than "looking at the plant."

As for your cube-babies, when the root pops through the bottom, you should have a few sets of leaves -- the original cotyledons and then a couple more sets. If you're there, the cube is ready to move to the next phase. For me, that meant putting them into bubble pots. They look small, but they're ready. With me, it was at 5 days. I was nervous, but it was the right thing to do. You don't need ph'd water until you start giving them nutes, and you're at least a week away from that. They should be 2 weeks old, and then start them at 1/4 nutes. You'd rather deal with a deficiency in a few weeks then kill them outright.

If they're ready to move to the larger rockwool cube, then move them. Their sisters may seem "behind" now, but they'll catch up by the time you move to flowering.

Good luck!

Also, I researched a lot about letting water air. Also not necessary. I used tap water (NYC) and my plants grew to monsters.

Hi Kryptoniteglo,

Thanks for the reply. Appreciate your help here. I prefer the whole measuring and calculating so yeah that's why I went this route.

I don't think my girls are at the stage you are picturing them at just yet. They are still just seedlings with their initial first leaves. They are in little prop cubes but they are poking through the little cubes at the bottom. That is why I am going to move them into the big cubes. Totally appreciate you telling me about your apprehension towards getting them in your hydro set up. It might help me when toying with that decision The fact that I've ph'd the water now won't be an issue will it? I thought I needed ph'd water to reduce the alkalinity of the rockwool or am I totally off base with that?

My main concern is not moving them into the big cubes swiftly? Is that going to be detrimental or if I do it in like 8 hours time once my water warms up. It was at 12 celsius when I started and around 18 now so probably needs another 4 - 8 hours.

Regarding the water we have shop called tesco like a supermarket that does just H2O for 17p for 2l. I thought when my seedlings were small this might be the nicest thing for them but I'll keep that in mind as I go on.
Thanks for your help very much appreciated

Ph matters only when you're feeding nutes because it affects the absorption. I know on my rockwool bale's label it says ph and add nutes, but that's really for clones, not for starting from seeds I think. Don't quote me on that because I've never worked with a clone, but that's what I'm thinking. But I know for seeds ph'd water isn't necessary -- but it won't hurt them, either.

You can wait 8 hours...it doesn't need to be that perfectly timed.

These aren't orchids -- it's a weed. You don't need a silk pillow and velvet gloves. It's more important not to over-treat them with nutes and light. You need the right amount, not too much!