RDWC Your help needed please...

Hi Guys,

Not new to this forum in terms of reading but newly joined to post. Not a complete beginner having done a few successful rounds on NFT but recently decided to venture into DWC for a change and to try something new. Problem is i seem to be falling at the first hurdle. I'm hoping someone can maybe point out something i could be doing wrong. OR perhaps just a bullet proof method they use that i can maybe mirror for the first part.
The problem is moving the small rockwool cubes to the net pots. Ive been doing this after noticing root growth on the underside of the cube. I've put some pebbles in the bottom of the pots (inch ish) and raised the water level of the system so bubbles ar kinda on the line of the bed of pebbles. Then put the remaining pebbles around to fit. Temp around 70f, ph around 5.9, chiller keeping food around 68f, EC about 1.1 (EC according to guardian)
Even after a week or two they don't seem to carry on growing much or at all. And some just die. I'm not top feeding as i think the cubes are keeping wet and i dont want to over water either. Only a 48w T5 propagation light in there but they're only about 2 inches high so assume that's sufficient?
Any ideas?

Look into rockwool and EC from the manufacturer and it has to stay wet but you may get algae on top depending on a few factors.
Seems like your water is probably chlorinated and the alkalinity is giving you EC control issues.

I use Grodan 1.5" starter cubes for my seedlings and clones.
After I get root growth developing, I'll place them in a 6" netlid.
I use approx. 2" of hydroton in the bottom of the lid and backfill after placing the cube in the netlid.
I keep the solution about 1" below the netlid and top feed the cube until roots drop from the net.
After the roots are in the solution, I stop top feeding.
Works every time.

1.1 EC?thats way to high. There either way too dry or too wet. I assume you’ve checked. Never had a clone or seedling die. In rdwc.

She'll acclimate in time don't stress, sometimes it'll take up to 2 weeks before they're happy.

Ok a few different things here. From everything I’ve read including the food chart 1.1EC is spot on for right now. I could try the top feeding instead I guess but I’m still surprised I’m struggling with what I’ve done as I’ve seen many videos of people being reliably successful doing what I’ve done. I could check the calibration on the EC but the guardian says it doesn’t need calibrating when new. I’m sure there has to be a major thing just not quite right

GBAUTO said:

I use Grodan 1.5" starter cubes for my seedlings and clones.
After I get root growth developing, I'll place them in a 6" netlid.
I use approx. 2" of hydroton in the bottom of the lid and backfill after placing the cube in the netlid.
I keep the solution about 1" below the netlid and top feed the cube until roots drop from the net.
After the roots are in the solution, I stop top feeding.
Works every time.

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could you let me know how much you top fed them roughly? I know there are alot of variables but roughly how many ml in how many days would be useful as a benchmark. thanks

myke said:

1.1 EC?thats way to high. There either way too dry or too wet. I assume you’ve checked. Never had a clone or seedling die. In rdwc.

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Actually it does seem like it should be nearer 0.7 youre right

MrTwarn said:

could you let me know how much you top fed them roughly? I know there are alot of variables but roughly how many ml in how many days would be useful as a benchmark. thanks

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I pour a 1/2-1 cup of solution over the cube/netlid about once a day until they drop.
I run Jacks 3-2-1 at full strength from day one.

GBAUTO said:

I pour a 1/2-1 cup of solution over the cube/netlid about once a day until they drop.
I run Jacks 3-2-1 at full strength from day one.

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Thanks - what EC is the solution under them/being poured on daily?

Usually runs around 1.5-1.7

MrTwarn said:

I'm hoping someone can maybe point out something i could be doing wrong

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MrTwarn said:

The problem is moving the small rockwool cubes to the net pots.

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rockwool sucks. next grow use something like a rapid rooter from GH

rkymtnman said:

rockwool sucks. next grow use something like a rapid rooter from GH

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Yeah I don’t like the stuff. Are the RR PLUGS better at not getting too wet?

Use a syringe to pull excess water from Rockwool.

Ok, we're transplanting here right? Bro honestly don't even play with the EC right now let's just get them settled. Would you measure EC when transplanting in coco? Really when you look at EC you're looking at the rate of which your nutrients are being taken in. For seedlings, especially in DWC don't need anything to get going except water for the 1st week or so. If you pH even better, but I wouldn't even think about nutes until they're up & ready. Start looking at EC when you're actually feeding them, not in acclimation b/c they're not really even eating until they get settled.

Ok thanks - I have a plan for the next week and expecting it to work! Will feedback then. Cheers

While I’m on here - regarding EC. I keep hearing two conflicting strengths. There are food charts that suggest starting around 1.1 and moving up at intervals. There are also people on here and other charts I’ve seen that suggest about half that. Could a few people comment on this matter so that I have some sort of base to go on? Would be really appreciated! Thanks again!

MrTwarn said:

While I’m on here - regarding EC. I keep hearing two conflicting strengths. There are food charts that suggest starting around 1.1 and moving up at intervals. There are also people on here and other charts I’ve seen that suggest about half that. Could a few people comment on this matter so that I have some sort of base to go on? Would be really appreciated! Thanks again!

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When they're ready, 1/2 strength or even less. They're seedlings they don't need much. You'll know when they're good to go.

Agreed 1/2 or even 1/4. Don’t over think this. It’s easy to add. Hard to take back.

I’ve run a whole grow without exceeding 1 EC why waste nutes.nutes companies want you too over feed they sell more products. That’s why there charts say to feed high.