DWC seedling question (HYDROTON)

biologist

Member
Hey everyone, first time poster here on RollItUp (used to post on another site that was shut down a while back).

I have always grown in soil up to now and I have decided to make the switch to DWC, so I educated myself as much as I possibly could on the topic, built myself a 5 gallon bucket with all the bells and whistles, and now I am good to go. I have some Tangerine Dream seeds (I know, I know, lots of controversy about these but lets keep that discussion for another day lol!) and I germinated them and placed them in a rockwool cube that was soaked in properly PHed water for a day.

I knew that I had the option of waiting for the seed to sprout (and for a few roots to pop out of the cube) before transfering it to my netpot, but I decided to go ahead and place the cube in my system right away. The reason for this is that i did not want to damage any roots if I transfered it later on. Ok, so here is my question for all the experts on the forums:

I placed my wet rockwool cube on top of a 1 inch layer of hydroton (with the water level in my bucket just below the netpots). I am planning on top-watering the cube whenever it needs it, until the roots grow enough to hang below the netpot and into the aerated water. My concern, however, has to do with the hydroton itself. Right not, I filled my netpot with hydroton which means that I my rockwool cube is completely surrounded (1 inch of hydroton on the bottom, as well as about 1 inch on top). Here is my question:

Will the new seedling find its way up through these rocks? Or, should I remove them, wait for the plant to start growing, and then add the hydroton to "secure" the stem in place?My reasoning in filling the netpot with hydroton right away was that I did not want any disturbances to the plant once it started growing, which may perhaps cause a stunted growth. I looked EVERYWHERE on these forums and elsewhere online, and cannot seem to find a clear-cut answer about this, so if someone could chime in I would REALLY appreciate it!!

Looking forward to your responses....
 

sworth

Well-Known Member
I'd remove them.
I've never tried, but I doubt they have enough strength to push through...and it's what she wants most of all; Light.
 

biologist

Member
Thanks for your reply! I understand your logic in that the plant benefits from an early exposure to light (makes sense, after all light is what drives photosynthesis). However, I can't help but think that when growing in soil the seedling has to first push through a certain amount of earth before breaking ground. I don't see what the difference would be in this case, apart from (like you said) the fact that maybe the hydroton rocks are simply too heavy for the young plant to work its way through.

I would still like others to chime in, if possible. Anyone ever experiment with this method and has some information that would enlighten me on the matter??

Once again thanks sworth for your input, any help is always greatly appreciated :lol:
 

firsttimeARE

Well-Known Member
The biggest problem I found with putting cubes directly in without roots was that it was hard for me to gauge how wet the cubes were not being able to pick them up and some plants died because of this.

The plant would probably have enough strength to break through, but why risk it? You're going to want that cube exposed while you top feed to gauge how dry it looks, so take those stones off the top. I usually weigh mine to gauge wetness and wait for like 50% of the bottom of the RW to be covered in roots until I transfer(takes about a week to two). Ive had these roots then hit the water in as little as 4 days.
 

biologist

Member
... annnnnddd I took off the top layer of hydroton. Makes sense that without seeing my cube, I can't really gauge how wet/dry it is. What I did is that I placed a glass bowl over my netpot for the time being, and there is always condensation so its almost like if the cube was in a propagation tray (but instead, its already in my DWC bucket setup). Since there is always condensation, should I even be top-feeding the cube fore the first week or so? Or will the ambient humidity (in addition to the water splashing on my netpot) be enough to take care of my up-and-coming lady??

Thanks for your input guys.
 

BigLittlejohn

Well-Known Member
I've always waited for the germed seed to sprout and a some roots poking through the bottom of the rockwool before I drop into my buckets. This usually happens for me by the third day after germination. My roots typically are in the water 4-7 days after dropping them into buckets.

I think you will be fine as long as the bottom layer of hydroton is getting wet. That will encourage your roots downward. I generally don't expose my rockwool cube to the light as it dries it out, so I cover it with hydroton, but I also don't top feed at all. With such a temperamental strain I'd be hesitant to fuck around with a lot of chances.
 

biologist

Member
I've always waited for the germed seed to sprout and a some roots poking through the bottom of the rockwool before I drop into my buckets. This usually happens for me by the third day after germination. My roots typically are in the water 4-7 days after dropping them into buckets.

I think you will be fine as long as the bottom layer of hydroton is getting wet. That will encourage your roots downward. I generally don't expose my rockwool cube to the light as it dries it out, so I cover it with hydroton, but I also don't top feed at all. With such a temperamental strain I'd be hesitant to fuck around with a lot of chances.
cool, thanks for contributing in this discussion! What I am understanding is that roots usually appear at the bottom of the rockwool cube BEFORE a sprout (cotyledons) is visible on top?? Can you confirm this?
 

dudeman222

Active Member
Will the new seedling find its way up through these rocks?

YES

I don't even top feed, just keep your water 1 inch above the bottom of the pot
and when the roots start to stick out the bottom, lower the water level
 

dudeman222

Active Member
I've always waited for the germed seed to sprout and a some roots poking through the bottom of the rockwool before I drop into my buckets. This usually happens for me by the third day after germination. My roots typically are in the water 4-7 days after dropping them into buckets.

I think you will be fine as long as the bottom layer of hydroton is getting wet. That will encourage your roots downward. I generally don't expose my rockwool cube to the light as it dries it out, so I cover it with hydroton, but I also don't top feed at all. With such a temperamental strain I'd be hesitant to fuck around with a lot of chances.

I agree with this guy
 

MiloTheDog

Active Member
Hey there biologist, Im currently growing Tangerine dream and this is what I did. I germinated the seed paper towel method on top of the cable box for heat. Once the "tail" was an 1" I put her in rockwool and straight into the dwc. I had trouble in the beginning with this strain so maybe she didn't like that, or maybe it had no effect. Either way, her roots eventually made their way into the reservoir.
 

kryptoniteglo

Well-Known Member
I germinate my seeds in rockwool but wait until the root has poked through the bottom about an inch before putting in the bubble buckets. Usually that means I have 1-2 sets of leaves and the plant is about 5 days from sprouting. During those 5 days, it's under a gentle cfl. Once it goes in the bucket, it's under a 400W MH light.

I've noticed I have a problem with damping off -- I'd say 1 out of 3 seedlings die from this, so I do try to keep the cube as dry as possible that first week, and yet not so dry that the seedling doesn't grow.
 

biologist

Member
My seedling has finally broken through the surface of my rockwool cube (I had previously removed the hydroton layer on top of the cube, and plan on adding more rocks as the plant grows).

My cube is still wet, and it getting splashed from underneath the netpot, so do you guys recommend I stop top-feeding all together? I figure she should be okay and this would actually promote the plant growing roots faster in the search for water. Also, the cotyledons are just opening now and I have a 150 hps light already on, but im keeping it a good 25 inches away for the time being to avoid burning the seedling. Is this a bad idea? Am I better off using a cfl for the first few days, or is a HPS placed very far away also a good option? Thanks for your input everyone, much appreciated!
 

hotrodharley

Well-Known Member
CFL is recommended. Be sure to do whatever you need to block any light of any sort getting to the res. Including light filtered through tops and sides of DWC units. Paint, Gorilla Tape (my favorite) and mylar with openings for the plants (or any other opaque material) are some of things people use.
 

biologist

Member
CFL is recommended. Be sure to do whatever you need to block any light of any sort getting to the res. Including light filtered through tops and sides of DWC units. Paint, Gorilla Tape (my favorite) and mylar with openings for the plants (or any other opaque material) are some of things people use.
I have covered my bucket and lid completely with reflective tape and have shined a flashlight in there to make sure no light escapes - I am OK on that front. Why is a CFL light recomended instead of a HPS placed further away? In nature, when a seedling comes out of the ground, it is exposed to the sun (albeit less strong than the full "summer" sun)... wouldnt this be replicated more accurately by using a HPS light, placed further away, than a CFL??

Must be something I'm missing here, because it seems that the consensus is definitely to use a CFL, I would just like to understand your reasoning. I am that type of person that hates doing things without understanding them, so please bear with me;)
 

elgatonegro420

Well-Known Member
to comment on dwcs and water. keep in mind the fundamental of roots and water. access but not too much to drown and throw in some o2. in my case im using a 5 gallon bucket for my finisher. if u can make one bucket use that intuitive mind to create a smaller version from a 3 gallon tote. this way u can avoid having to hand feed and it doesnt take much water becasue the roots are so young. i have a container with holes cut out to fit 5 3 inch rockwool cubes. i put nails through to suspend in the lid(i can add pics). when roots aare about to get tangled remove and put in 5 gallon bucket. i did this and my plant sloweded for 1 day and shot off. i have airstones in everything but my prop tray. currently testing airstones and gang valves. im quite the nerd and found somewhere to eploit it!!
 

elgatonegro420

Well-Known Member
and for the fls and hps in the early stage the plants like the blue light from ur fls. im using a 4'8bulb setup here. i can turn half off with a switch. u get good light to plants cuz they emit way less heat and remember they like this color early. since u can adjust them to within a few inches especially with a cheap fan that blows on the bulb (air cooled now) u really get to personlize to ur likin. the hps is better with that orange red specctrum for bloom. plus since the plant is more mature it can handle more. in a nutshell. i gotta check my hobby myslef but i think i can help out some
 

BigLittlejohn

Well-Known Member
cool, thanks for contributing in this discussion! What I am understanding is that roots usually appear at the bottom of the rockwool cube BEFORE a sprout (cotyledons) is visible on top?? Can you confirm this?
No, I didn't mean that. I meant that before I drop the rockwool cube into my buckets, I wait for the germed seed to sprout and show the root popping through the bottom which in my experience happens shortly after or at the same time the thing sprouts. Personal preference, not sure there's any science or anything behind it but until both of those things happen, I keep it in the propagation tray under a small T-5. That's when I simply drop that into the bucket, with a layer of hydroton on the bottom and carefully placed around and on top of the cube.
 

SteezyDee

Well-Known Member
What Dudeman said, an HPS further away runs the risk of stretching the plant but a CFL will be suffice to promote seedling growth and will be able to be kept close enough to avoid stretch.

You did everything right, germing then placing the seed in rockwool, after you do that you placed it in the net pot with one inch of hydroton on bottom, good as well.. From that point all you had to do was keep the water level touching the bottom of the net pot which would keep that lower layer of hydroton moist and promote the seedlings root growth downwards.

Also, like everyone said, you dont have to cover the rockwools top in hydroton.. Once you see it sprouted you can then place more hydroton to cover up the rockwool and support the stem of the seedling as it grows.
 
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