Top Feed RDWC seedling issues

[ldm321]

Hello fellow growers

This is my second grow in deep water culture.
I am growing 3 “707 headband” and 3 “the new” both from humboldt seed organization.
All 6 seedlings were started in rockwool cubes 8 days ago.

After their first set of serrated leaves began forming, I moved them into my RDWC. My system has a drip ring that keeps the 6” net pots of hydroton saturated. I have a 1750GPH pump that supplies all 6 buckets with air (2 air stones in each bucket).

I filled the system with 880PPM solution containing:

Starting with R/O water
Mills Basis A
Mills Basis B
Mills Vitalize
Mills Start R
Botanicare Cal-Mag
Botanicare Silica Blast
Hygrozyme
SNS 209
Great white mycorrhiza

I check on the plants many times a day and the conditions are always pretty similar:

Air Temp: 77-80
Relative Humidity: 40-70
Air Speed: slight movement of leaves
Water Temp: 70
pH: 5.6-6.0
PPM: rose from 880-1000 over a week
(I have added R/O water to bring it down to 620PPM)
Water level: hasn’t changed yet
[CO2]: 800PPM
PPFD: 250 μmol/(m^2 x s)

The “707 headband” seedlings are looking better than “the new” in my opinion. 2 of the “707 headband” are showing slight burning in the tips of their serrations, one of them is looking pretty solid all around. 2 of “the new” however, are super droopy, no sings of burn though.

I turned off my top feed because I figured the plants were over watered (rockwool cubes were wet to the touch). I did this yesterday and they’re still droopy and tip burn is spreading slightly.

Any thoughts or opinions would be great, it took a long time for me to get my hands on these genetics and I don’t want to loose them.

Thanks everyone!

“707 Headband”

“The New”

 

[Anthem]

Dude I got the 880 PPM and that was all I needed to see. They are going to fry at that size and PPM.

 

[ldm321]

Dude I got the 880 PPM and that was all I needed to see. They are going to fry at that size and PPM.

^^ I figured it was too hot for them since the PPM was going up over time so I lowered it to 600PPM, you think that’s a good spot for them at this stage of growth or even lower?

 

[Anthem]

^^ I figured it was too hot for them since the PPM was going up over time so I lowered it to 600PPM, you think that’s a good spot for them at this stage of growth or even lower?

Dude that is what guys in DWC sometimes feed at peek of flower.
@Aqua Man is a DWC guy, he can take it from here.
May I ask you a stupid question, what made you believe 880 was OK for a seedling?

 

[Anthem]

Do a rez change now and mix your nutrients to 200 PPM for now. Aqau Man will get back to you when he is on line. But the longer you wait to lower the PPM's the worst the problem will be for the plant.

 

[ldm321]

Do a rez change now and mix your nutrients to 200 PPM for now. Aqau Man will get back to you when he is on line. But the longer you wait to lower the PPM's the worst the problem will be for the plant.

Okay I’ll do a little flush and then feed it lower ASAP. I went based off of the mills nutrients online chart. I mixed exactly what they listed for a “light feed”. You don’t think there was an overwatering issue at play. Simply over feed them? Thanks.

 

[Moe.Red]

There's enough salt on that hydroton that you could get away with a straight non nute water change and let them breathe for a few days then slowly ramp it up to a normal level. At this stage, 80 is a lot IMO

 

[Anthem]

There's enough salt on that hydroton that you could get away with a straight non nute water change and let them breathe for a few days then slowly ramp it up to a normal level. At this stage, 80 is a lot IMO

I agree it could be lower, but I really doubt that he has RO water if he started out at 880 PPM's. I asked him why he thought 880 was OK but no answer so far.

 

[ldm321]

I agree it could be lower, but I really doubt that he has RO water if he started out at 880 PPM's. I asked him why he thought 880 was OK but no answer so far.

I am using reverse osmosis water, my blue lab meter says it has 0PPM. I mixed up all the additives up to 880 PPM. I’ll feed them a very weak solution. You guys don’t think the roots are lacking oxygen?

 

[ldm321]

Why do the damn nutrient companies say that such high levels are okay!?!?

 

[Anthem]

Why do the damn nutrient companies say that such high levels are okay!?!?

Well what would you do if you were in the business of making and selling nutrients?

 

[Anthem]

I am using reverse osmosis water, my blue lab meter says it has 0PPM. I mixed up all the additives up to 880 PPM. I’ll feed them a very weak solution. You guys don’t think the roots are lacking oxygen?

Are the roots thru the rockwool block?

 

[smokedareefer]

Keeping the rock wool cubes sopping wet isn't a good idea. Once the roots are in the water there's no reason to water from the top.

My ppm on my bluelab seldom goes above 600 during the entire grow

 

[ldm321]

It’s hard to tell if they’re through the block of rockwool yet. They’re not through the net pot yet

 

[airedog]

Am i the only one wondering about that 1750 gph pump that feeds just 6 buckets? What are you doing to make the flow and pressure managable?What are you using for drain/return lines?

 

[ldm321]

I definitely agree with everyone that the nutrients are too hot. I feel like the “overwatering”/lack of oxygen is the biggest thing causing the droopiness though. Any one able to confirm that assessment? Or do you guys think the dropping leaves are just a result of the nutrient concentration being too high?
Thanks again.

 

[Anthem]

I definitely agree with everyone that the nutrients are too hot. I feel like the “overwatering”/lack of oxygen is the biggest thing causing the droopiness though. Any one able to confirm that assessment? Or do you guys think the dropping leaves are just a result of the nutrient concentration being too high?
Thanks again.

You have a few problems and the PPM is the first that jumped out. If you use the search tool put in dryback or rockwool cubes and you should be able to get some information about dryback. The root system in the rockwool needs time with low or little water in the block to get oxygen to the roots. Once the roots are out of the block this is less of a problem. You can also pick up the air pot and check it for weight. You really do not want that much water in the rockwool all the time. Transitions plants to DWC is tricky.

 

[Anthem]

The droopy leaves can be caused by too much water, which is probably the case but take a look at the deformed discolored leaves also. This is coming from nutrient overload or possible lockout. I do not know if or how long it will take for them to get healthy and you have already stressed the plants. If you can afford it I think I would start with new seeds, but I am anal with shit being prefect.

 

[ldm321]

Am i the only one wondering about that 1750 gph pump that feeds just 6 buckets? What are you doing to make the flow and pressure managable?What are you using for drain/return lines?

1750GPH air pump

 

[ldm321]

The droopy leaves can be caused by too much water, which is probably the case but take a look at the deformed discolored leaves also. This is coming from nutrient overload or possible lockout. I do not know if or how long it will take for them to get healthy and you have already stressed the plants. If you can afford it I think I would start with new seeds, but I am anal with shit being prefect.

I could buy new seeds but it would take a long time for them to come in. You really think these are toast?