DWC Overwatering or Underwatering?

Portable A/Cs have to be vented outside. If you already knew that then please disregard the previous advice.

All the early fan leaves have died and fell off by themselves. The remaining leaves are the new growth shoots from between nodes.

It looks nice and neat, but as shown in the pictures the spottings have started to appear on the new leaves as well. They will eventually turn brown and die too lol

I've been trying hard to save these plants but there's not much I can do now.

Ordered some Cal-Mag today as a last resort, but I can't think of any reason it should lack Ca or Mg. I'm using tap water(although pretty soft at 100ppm) and dynagro nutes. Last time I grew indoors was 10 years ago using the same tap water and nutes, didn't have this problem then.

jronnn said:

raise the water level so the bubbles/water is touching the bottom of the cubes... then drop the water level back down once the roots grow out of the net cup into the tote. also highly recommend you use hydroguard, its a cheap way to basically guarantee you wont get root rot. id give them a light feed too probably like 3-400 ppm

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why do you think the water level should be dropped? any time I have seen that there are only a few feeder roots with a huge root ball hanging some 6' below. just how are a few feeder roots supposed to transfer all the nutrient the ball has in it/

ime rockwool sucks and it's a bio-hazard (coco pellets rock), but since you already committed, use an eye dropper to hand water.

PetFlora said:

ime rockwool sucks and it's a bio-hazard (coco pellets rock), but since you already committed, use an eye dropper to hand water.

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Hey thanks for the reply. Yea I agree there are better alternatives to rockwool... I would like to use GH rapid rooters as initial medium if they were available in my region. Or maybe next time I will put germinated seeds directly into hydroton or perlite in net pot. Or I'll consider coco pellets too.

But anyhow I'm past that stage and roots are growing nicely now. I just have that rust spot problem as you can see in the recent pictures. What does it look like to you?

PetFlora said:

why do you think the water level should be dropped? any time I have seen that there are only a few feeder roots with a huge root ball hanging some 6' below. just how are a few feeder roots supposed to transfer all the nutrient the ball has in it/

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funny you say that, i personally do keep the water level touching the netpot thorughout the plants life because i see no benefit to keeping the water level a couple inches below the netpot... I just told OP to drop the water level after the roots grow out because that seems to be the DWC standard and i dont want to further add to confusion

jronnn said:

funny you say that, i personally do keep the water level touching the netpot thorughout the plants life because i see no benefit to keeping the water level a couple inches below the netpot... I just told OP to drop the water level after the roots grow out because that seems to be the DWC standard and i dont want to further add to confusion

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and yet you just did

Once roots get established the first inch or more of the roots coming out of the pots are just pipelines bringing water and nutes to the plant. Same with all the ones in the pots so people that top feed past the first few days are wasting their time. Those pipelines do not absorb water or nutrients. All that goes on at the tips of the roots whether in hydro or soil.

I keep the level an inch below the pots and only top up once the level drops to 3 or 4". Even that low the popping bubbles are still soaking the inside of the lid so the pots are getting an aeroponic bathing all the time. That way I only have to mess with the nutes every three or four days. I sometimes won't even go downstairs to check on them for 3 days. I'm old and lazy and going up and down the stairs hurts.

eldinrhee said:

All the early fan leaves have died and fell off by themselves. The remaining leaves are the new growth shoots from between nodes.

It looks nice and neat, but as shown in the pictures the spottings have started to appear on the new leaves as well. They will eventually turn brown and die too lol

I've been trying hard to save these plants but there's not much I can do now.

Ordered some Cal-Mag today as a last resort, but I can't think of any reason it should lack Ca or Mg. I'm using tap water(although pretty soft at 100ppm) and dynagro nutes. Last time I grew indoors was 10 years ago using the same tap water and nutes, didn't have this problem then.

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It looks like low Ca and maybe it's something in your tap water now that wasn't there 10 years ago causing it. Could be higher in Mg now and blocking Ca absorption.

100 is not bad but when you don't know what that ppm is made up from it's impossible to tell what's in it without a detailed water analysis report that you should be able to get from your provider for free. A lot of towns post them on their websites or a quick phone call will get you one emailed to you.

I only use RO or distilled so don't have to wonder if my water is causing my problems.

PetFlora said:

ime rockwool sucks and it's a bio-hazard (coco pellets rock), but since you already committed, use an eye dropper to hand water.

Click to expand...

Rockwool is just fiberglass like the stuff used in the walls of your house and the tiny amounts that a home grower would use in a lifetime would add up to a bundle of house insulation. Dozens of those bundles are used in an average bungalow so you should aim your environmental concerns to a target that actually matters.

Just sayin'.

I start my seeds in soilless and put the whole plug in net pots when doing DWC. Never real soil tho as the bacteria in it can cause root rot problems as I found out over a decade ago.

OldMedUser said:

Rockwool is just fiberglass like the stuff used in the walls of your house and the tiny amounts that a home grower would use in a lifetime would add up to a bundle of house insulation. Dozens of those bundles are used in an average bungalow so you should aim your environmental concerns to a target that actually matters.

Just sayin'.

I start my seeds in soilless and put the whole plug in net pots when doing DWC. Never real soil tho as the bacteria in it can cause root rot problems as I found out over a decade ago.

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I do whatever I can to reduce my carbon footprint. I use coco pellets as start seeds/clones

I have been following various grow sites for many years. The number of people using RW is enormous

PetFlora said:

I do whatever I can to reduce my carbon footprint. I use coco pellets as start seeds/clones

I have been following various grow sites for many years. The number of people using RW is enormous

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I'm not one of them. Tried it over 15 years ago and didn't like it so just use soilless to sprout seeds, root clones or stick the seeds right into pots of soil to sprout. My DIY bubble cloner seems to work fine so I can root cuttings in water and use them where ever I need them.

Coco is one of the best to use for sure but still has it's impact. Takes a lot of clean water to flush it before it can be used and the manufacturing process to make it into pellets uses a substantial amount of energy.

Everything costs something.

Update:

I switched to 12/12 4 days ago. I think I have the space to keep 2 out of 5 plants, but they're not showing sex yet.

They seem healthy though. Started showing alternating nodes so hopefully flowers will come soon.

It's getting crowded.

people usually put small plants into a small space forgetting the plants will grow. you just learn the lesson and carry on.

How close to the canopy is your light? That might tell us a little more of what we need to diagnose judging by the curling leaves

You're going to need to thin those out too if you just now flipped, they'll still at least double in size throughout the stretch.

propertyoftheUS said:

How close to the canopy is your light? That might tell us a little more of what we need to diagnose judging by the curling leaves

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400w actual draw COB LED about 30 inches above plants.

I plan to remove 3 of 5 plants as soon as I can sex them

Does it produce much heat? It looks like they are transpiring way too much

Uh???? What ever happened?

People insist on using rockwool cubes in DWC. It's very hard for a beginner to water rockwool properly, especially in the seedling stage. It's cheap but rockwool only really works well with flood and drain tables IMO.

I think you need to stop looking at YouTube videos and Google searches for guidance.

Edit: Old thread