No growth in veg 4 weeks old with 2 sets of leaves

[dauzer]

Hey,

My plants aren't growing!! And I need some help. I'm at the stage now where I'm thinking about throwing them out and starting again. Can't figure this out and can't afford to wait another few weeks as I won't be around to finish them.

Here's some info from what's been happening so far

I have 2 sets of incredible bulk growing in a 2.4m x 2.4m tent. 4 in soil and 8 in IWS flood and drain system.

All 12 were started in the same propagator and got transplanted into 1" root root cubes. After 2 or 3 days they were all moved to pots.

4 IBs went into 18L pots with BioBizz All mix soil under a T5 light

8 IBs went into 9L Aqua pots with Gold label 80/20 Mix. 80 Clay Pebbles 20 Coco under a T5 light.

Within a few days the soil started to shoot up and they look really healthy. About 6 or 7 sets of leaves and very close nodding.

The IBs in hydro are just not growing. They have 2 set of leaves. At first I thought it was due to the medium having no starting nutes so I gave them 1/4 strength AN connoisseur after 2 weeks. Within a few hours the leaves started to turn a light green / yellow colour so I flushed them. 2 weeks later and they still haven't grown. So I gave them another feed with 1/4 strength, again the leaves are turning light green / yellow colour. I'm assuming it's too much of something.

-Temp: Day 28C - Night 20C
-Humidity: Day 55% - Night 60%
-Water res temp: 21C
-Tap water starting 370ppm - after 1/4 nutes 780ppm
-pH starting off is 7.6, after sitting over night it climbed to 8.4. Adding pH down gets it to 5.5 but it starts to climb again to 6.1
-Air pump with 2 air stones in the res mixing the water so it doesn't stagnate

Both the soil and hydro have them same room conditions. I know the temps are a little high and humidity a little low but the soil IBs are flying it.

What am I doing wrong ? It's my first time using a hydro system so I'm sure there is something wrong but I can't see it.

Any input is appreciated. Help save the babies .

 

[Scientific]

Can you post a picture?

Based on what you've said and other hydro grows I've seen, I'm going to guess that you are drowning the roots of the hydro plants. That often happens when they are in rock wool. (Is that what your "root cubes" are?) See post #4 forward on in this log.

 

[dauzer]

Sorry yea should have stuck up pics. Got side tracked last night.

The biggest IB in hydro

Now look at the soil IBs

 

[dauzer]

Can you post a picture?

Based on what you've said and other hydro grows I've seen, I'm going to guess that you are drowning the roots of the hydro plants. That often happens when they are in rock wool. (Is that what your "root cubes" are?) See post #4 forward on in this log.

My medium is root riot cubes and there in a 80/20 pebble coco mix. For the first 2 weeks i didn't have the flood and drain on, i was hand watering every 2 days or so. But yeah after looking through your posts i can see what what you mean.

Iv just turned off the timer now so they wont be getting any more auto feeds. I will wait til the pots dry out a bit and hand water again. Its hard to tell when they are dry. With soil you can really feel the weight of the water in the pots but with these they weigh pretty much the same before and after they get watered. Most of it runs off. Iv also just added the 2x 600 mH lights in air cooled hoods to see if its was lack of light. Although the soil IB got to the height they are now under the same T5

 

[Scientific]

Thanks for the pix. I'm pretty much convinced now that it was in fact too much water. I suspect that there is a big difference between just pebbles and a pebble/coir mix--that the coir is holding more water and taking up air space, suffocating the roots.

If it was my grow, I think I'd be tempted to repot with just hydroton and no coir. If you want to keep the coir, you're obviously going to have to reduce your flooding schedule.

That good news that in my experience, as soon as the roots start breathing, the plants make a very rapid comeback (as you can see in that grow log I mentioned in which the plant started to snap back within 24 hours).

Good luck and happy growing!

 

[Scientific]

By the way, just plain hydroton "pebbles" can hold and can even wick a surprising amount of water for a long time. If you put a couple of handfuls of hydroton in a small pot and put the bottom layer in water, you'll see that all it becomes wet within a few hours, and it stays wet for a long time. If you don't have anything like coir taking up the air spaces, it's hard to overwater with hydroton because it "breathes" so well. The coir in your pots has taken away that safety net.

 

[dauzer]

Thanks for the pix. I'm pretty much convinced now that it was in fact too much water. I suspect that there is a big difference between just pebbles and a pebble/coir mix--that the coir is holding more water and taking up air space, suffocating the roots.

If it was my grow, I think I'd be tempted to repot with just hydroton and no coir. If you want to keep the coir, you're obviously going to have to reduce your flooding schedule.

That good news that in my experience, as soon as the roots start breathing, the plants make a very rapid comeback (as you can see in that grow log I mentioned in which the plant started to snap back within 24 hours).

Good luck and happy growing!

Yeah I'm thinking the same now. Iv turned off the flood and drain. I'll give it a day or two and let it dry out. Iv already bought the AN Coco grow and bloom nutes so I'll be stuck with the coco mix for now but my next grow I will switch to the all hydroton and use the connoisseur. I think the 600 HID are helping, whether it's due to more intense light or it's drying out the pots quicker.

Thanks for the help .I'll update in a few days and let you know how their getting on.

 

[Scientific]

More light is always good.

 

[dauzer]

Scientific, do you have any experience with AN pH perfect nutrients ? I'm getting some concerning readings after adding Sensi Coco Grow A&B to the res. My starting pH from the tap is 7.5. After adding the base nutes it dropped by .4 so my pH now is 7.1 which too me is way to high for hydro. I was expecting a pH range of 5.6-5.8


Straight from tap water

After adding 1/4 strength Sensi Grow A - 150ml added to 150L res

After I added the 1/4 strength of Sensi Coco Grow B - 150ml added to 150L res

 

[dauzer]

P.S iv just order an iSpring RO system so will have that set up next week to get that ppm to 0

 

[Scientific]

Scientific, do you have any experience with AN pH perfect nutrients ? I'm getting some concerning readings after adding Sensi Coco Grow A&B to the res. My starting pH from the tap is 7.5. After adding the base nutes it dropped by .4 so my pH now is 7.1 which too me is way to high for hydro. I was expecting a pH range of 5.6-5.8

500 PPM!? I think that's often referred to as "liquid concrete."

Bear in mind that when you get the PPM down low, you may need/want to supplement calcium and magnesium. Or, if your water has lots of Ca and Mg (check your water supplier's website), you might be able to dilute your RO with some tap to get some free ions.

I do not have experience with the AN pH Perfect system, but I recently asked a question about it on the hydroponics forum (which I suggest you visit), and got very positive responses, that yes, it does stabilize pH. (The pH on my grow was given to falling drastically every night.)

I think you would get much more typical results with better water.

I know at least one manufacturer makes a "hard water" version.

I would suggest really reading up on the AN system and follow their instructions very carefully, with the one possible exception of maybe diluting the mix a little more than is called for. Often the doses that are given by manufacturers are at the high end.

 

[Planter420]

Your roots aren't in the bucket yet. It must be having a difficult time making it through all that hydroton. Best thing for that would be some type of root expander and a drip ring setup. We made ours with vinyl tubing and a T fitting. Like they're saying above the rockwool tends to retain a lot of water. If you're top feeding the hydro plant water around it not at the stem. You want the roots to follow the water into the bucket. And that's a super deep net pot as well you gotta stRt em further down and add hydroton when she grows a bit taller. Many diff ways to solve the slow start issue. In our experience though if you had a drip ring setup to pump water from your res to the plant for fifteen mins every two hours it helps a great deal. Our fastest was ten days roots well into the water. I wish you the best of luck sir and there's some real knowledgable members on this forum that have a ton of tips and tricks.

*Misread I thought you were in a DWC setup.*

 

[dauzer]

500 PPM!? I think that's often referred to as "liquid concrete."

Bear in mind that when you get the PPM down low, you may need/want to supplement calcium and magnesium. Or, if your water has lots of Ca and Mg (check your water supplier's website), you might be able to dilute your RO with some tap to get some free ions.

I do not have experience with the AN pH Perfect system, but I recently asked a question about it on the hydroponics forum (which I suggest you visit), and got very positive responses, that yes, it does stabilize pH. (The pH on my grow was given to falling drastically every night.)

I think you would get much more typical results with better water.

I know at least one manufacturer makes a "hard water" version.

I would suggest really reading up on the AN system and follow their instructions very carefully, with the one possible exception of maybe diluting the mix a little more than is called for. Often the doses that are given by manufacturers are at the high end.

Yup. Liquid concrete looks about right. Here's the res after I drained the system lol

I just wrote to AN, this was the response from the rep about my pH being 7.1 after the base nutes.

"The pH Perfect increases the spectrum of the pH between 4.0 and 8.0 so in that case the 7.1 is just fine. If you were to use a non pH Perfect nutrient here is how the pH should look like:

Soil approx.. 6.3
Hydroponics approx.. 5.5
Coco approx.. 6.0"

So all good on the pH side of things. The RO system should sort the liquid concrete .

 

[dauzer]

Your roots aren't in the bucket yet. It must be having a difficult time making it through all that hydroton. Best thing for that would be some type of root expander and a drip ring setup. We made ours with vinyl tubing and a T fitting. Like they're saying above the rockwool tends to retain a lot of water. If you're top feeding the hydro plant water around it not at the stem. You want the roots to follow the water into the bucket. And that's a super deep net pot as well you gotta stRt em further down and add hydroton when she grows a bit taller. Many diff ways to solve the slow start issue. In our experience though if you had a drip ring setup to pump water from your res to the plant for fifteen mins every two hours it helps a great deal. Our fastest was ten days roots well into the water. I wish you the best of luck sir and there's some real knowledgable members on this forum that have a ton of tips and tricks.

*Misread I thought you were in a DWC setup.*

Yeah actually when I lift the aqua pot out of the buckets the roots have just started to poke through. I thought they would have been longer or more developed as this stage. Definitely a lack of oxygen.

That drip system sounds like an idea. With the 8 pots for flood and drain I could rig some lines up to a T and Elbow connectors. What size pump do you use ? Are you just using the drip during the early stages of veg or throughout the grow ?

Always great to have such experienced growers stop by .

 

[Planter420]

Soon as the roots touch the water I pull the tube. It's a very small submersible pump. Doesn't heat the water up and uses very little power. If your roots are showing then the air stones should be popping bear bubbles and keeping the roots wet. You're set now she may be a little stunted but she will recover. but usually once the roots hit the water the growth rate is double that of soil so I wouldn't be surprised if the hydro plants eventually surpass the soil ones. With hydro you want that taproot in the water as fast as possible. Less media between bottom of rw and bottom of net pot. And the roots will follow the water. You having any material get in the res at all? Never used anything but hydroton in hydro.

 

[Planter420]

And we haven't been doing this very long either but you'll find the learning curve at this forum is a lot steeper thanks to the awesome members here on 420. After one grow you will be all the more wiser and you will learn a lot.

 

[dauzer]

Soon as the roots touch the water I pull the tube. It's a very small submersible pump. Doesn't heat the water up and uses very little power. If your roots are showing then the air stones should be popping bear bubbles and keeping the roots wet. You're set now she may be a little stunted but she will recover. but usually once the roots hit the water the growth rate is double that of soil so I wouldn't be surprised if the hydro plants eventually surpass the soil ones. With hydro you want that taproot in the water as fast as possible. Less media between bottom of rw and bottom of net pot. And the roots will follow the water. You having any material get in the res at all? Never used anything but hydroton in hydro.

Once the pots dry out a bit ill try them again with some 1/4 strength Sensi Coco and some root stimulator. Iv just checked the pots again this morning and there still pretty damp, the bottom of the buckets have some water left over from the drain so iv cleaned that up and left the pots open a bit to dry out. I wont be using a Coco mix again, sort of defeats the point of having flood and drain system if i can only feed once a day.

Yeah i never even thought about material getting into the res when i was choosing the medium. The Coco fibers are going through the lines and will eventually block up the floats an or the pumps or pumps. I need to look into a getting a screen to stop material from escaping the buckets. This coco is becoming a bit of a challenge, wish i had of went for all hydroton. Never again lol

 

[Planter420]

You live and you learn brother I never did flood and drain but if you do any kinda hydro, hydroton is your best friend lol

 

[dauzer]

True that, lesson learned lol. I knew by switching from the soil to hydro it was going to throw up some challenges. All a leaning curve I suppose and I will know what to do and not to the next run. Working out the kinks .

I will pop in and update next week. Hopefully they will be ready for week 1 of veg