Critical Kush (Barneys Farm)

Hello everyone.

Things seem to have started off well but I have encountered a problem.

Strain: Critical Kush (Barneys Farm)

Grow Method: DWC

Nutrients: AN Sensi Grow and Bloom

Lighting: PlatinumLed P300

Location: Grow Tent with Inline Exhaust fan and carbon scrubber

So I started out by germinating my seed using the towel method then placing it in vermiculite until she generated a root system and cotyledon appeared. After that I rinsed off the vermiculite placed her in a neoprene collar and into my simple DWC system (Rubbermaid tote with air stone). After a few days I noticed she was growing but leaves had a slight yellow color so i added 8mL of part A and B sensi Grow to around the 2-2.5 gallons of water in the tote (around 1/5 strength, at a recommended 16mL per gallon).

She was doing amazing, incredibly green and vigorous growth. At around the 4th node I decided to do a reservoir change and up the nutrient strength to 24 mL (around 3/5 strength). This is when bad things begin happening, within a few hours the lowest fan leaf set had curled up and became crispy to the touch. I became worried and immediately thought of nutrient burn so I diluted my reservoir by half (replaced half of its water with fresh tap water. I also checked the pH using pH strips which indicated pH in the high 6 range, so I added a little lime juice to drop it back down to around 5.5-5.8. The next day I noticed that the complete set of lowest fan leaves were totally dried out and crumbling, so I removed them with a sterile blade.


The next largest fan leaves seemed to begin drying out, so I rinsed off the roots and did a complete flush for 2 days under which time I noticed no significant change in the plants appearance.





As of two days ago I added nutrients back again at the original 1/5 strength and today (3 days later) the current lowest set of fan leaves have turned almost completely yellow and the newest growths are beginning to show browning on the tips. So at the moment I did another flush and she’s currently sitting in just plain tap water. What I have noticed is that she is rapidly growing new branch roots from the upper portion of the tap root and that the roots that are submerged are brown and seem very soft like wet string. The pH is around 6 at the moment and im not sure about what else to do. She is on a 24 hour light on cycle.

You may have root damage, that is very small I would back off on the nutrients until its larger and starts looking hungry.

Update:

After 24 hours of being flushed and running an aggressive strength of gold zone there are minimal changes to the top of the plant but quit a significant change in root zone. The new roots more than doubled in size since I last checked.

At this point im wondering a few things:
1) When should i start her back on nutes (and what strength)
2) What should I do with the brown slimy roots if anything at all (will they fall off?)
3) I slightly adjusted her stalk in the neoprene collar so that she is now closer to the water, will this cause any significant amount of stress?

I have been reading more into DWC and aeration of water and have come across Venturi injectors. I then found two of my submersible pumps and discovered that they both contain Venturi adapters for them.

Pumps:
Ecoplus Eco 633
Ecoplus Eco 185

I have decided to take advantage of this and design an easier to use DWC system. It will consist of two 3 gallon Rubbermaid totes linked together using pvc bulkheads (The line from grow area to reservoir will use 1 inch pvc and the injector port from pump to grow area will use half inch pvc. This is to prevent overflow and allow draining to occur quicker than filling.)

The injection port between the two totes will consist of two valves one which will lead to outside the system to allow easy draining and one that connects into the grow area. The purpose of using two is simply for a price convenience since a 3 way valve costs $15+ and a normal valve only costs $1-$2. To use, the drain valve will be opened and connected to a tube that will drain to a collection container and the second valve will be closed to prevent the pump from emptying water back into the system.

In this system he pump will both keep the water in constant motion and the venturi will constantly dump oxygen rich water into the grow area.

Now the question is should I use my eco 633 pump or my 185, I estimated that at optimal fill level each tote holds approximately 7 L of water or 14 total or around 3.7 gallons. I suspect that due to the small volume the eco 185 would do fine and be less noisy however do to the increased rate of the 633 the venturi would operate and a higher draw and deliver more oxygen.

What do you all think, any feedback would be great, I've included a drawing of the system

My advice is to cut off the dead roots, they will cause root rot if they stay in there. Are you using anything like rhizotonic or rhyzofuel? This stuff works great to build strong root systems.
From my experience, you need more aeration for the roots so if you can get more in somehow, your plant will benefit from it. Just be wary of using a bigger pump as it will increase the temp in your res. What temp is your res by the way?
With nutes, it looks time to start feeding but I'd feed at 1/4 strength to start with and increase each week if it handles it.
Otherwise, your system looks like it should work well

eastcoastmo said:

My advice is to cut off the dead roots, they will cause root rot if they stay in there. Are you using anything like rhizotonic or rhyzofuel? This stuff works great to build strong root systems.
From my experience, you need more aeration for the roots so if you can get more in somehow, your plant will benefit from it. Just be wary of using a bigger pump as it will increase the temp in your res. What temp is your res by the way?
With nutes, it looks time to start feeding but I'd feed at 1/4 strength to start with and increase each week if it handles it.
Otherwise, your system looks like it should work well

Click to expand...

At the moment Ive decided to stick with a sterile condition res using dutch master gold zone, which seems to be working quite well.

Is there a way to know for sure if the roots are indeed dead? I am only hesitant because I would hate to unnecessarily remove live plant tissue. The res is sitting at a flat 25C (77F)

Ok cool, the gold zone should do the same thing, if it's working then keep using it.

Your res temp is bordering on too warm and you're risking root rot. Below 23C will prevent root rot and slime. I keep mine on 22C and have never had an issue
Root pruning won't do it any harm, it may stunt it for a few days but the gold zone should pick them back up after a few days. Those roots look like the start of root rot to me, I'd be getting rid of them.

eastcoastmo said:

Ok cool, the gold zone should do the same thing, if it's working then keep using it.

Your res temp is bordering on too warm and you're risking root rot. Below 23C will prevent root rot and slime. I keep mine on 22C and have never had an issue
Root pruning won't do it any harm, it may stunt it for a few days but the gold zone should pick them back up after a few days. Those roots look like the start of root rot to me, I'd be getting rid of them.

Click to expand...

I dont really have a way to reduce the temperature besides using a chiller which I feel would be too costly and large for a single plant (unless they sell small ones?). Also with my newly designed system will effectively be doubling water volume and perhaps that will lower the temp slightly, ive decided to go with the 185 pump to keep the temps as low as possible.

Ok cool ill snip off the brown roots asap.

On a separate note referring to the DWC system I sketched I was thinking instead of have a single submerged line at the bottom of where the roots sit I can place two PVC lines above the waterline to eject water towards the waters surface to create a waterfall like effect. According to what ive read in post #15 a waterfall approach yields the highest amounts of dissolved oxygen even if at a very small difference. I feel the spray generated from the waterfall effect will not only increase the level of dissolved oxygen but also mist the upper roots that aren't able to reach the water.

GrapeNut said:

I dont really have a way to reduce the temperature besides using a chiller which I feel would be too costly and large for a single plant (unless they sell small ones?). Also with my newly designed system will effectively be doubling water volume and perhaps that will lower the temp slightly, ive decided to go with the 185 pump to keep the temps as low as possible.

Ok cool ill snip off the brown roots asap.

On a separate note referring to the DWC system I sketched I was thinking instead of have a single submerged line at the bottom of where the roots sit I can place two PVC lines above the waterline to eject water towards the waters surface to create a waterfall like effect. According to what ive read in post #15 a waterfall approach yields the highest amounts of dissolved oxygen even if at a very small difference. I feel the spray generated from the waterfall effect will not only increase the level of dissolved oxygen but also mist the upper roots that aren't able to reach the water.

Click to expand...

Yeah that sucks man, but those temps mean you are playing with fire, any warmer and you risk losing your crop to root rot and that shit sucks balls! Can you put a frozen bottle of water in there every day to try and lower temps? Even put in an airstone as well to keep the oxygen up higher... sorry man, I'm not trying to cause you any grief, I just don't want to see your grow go to shit

The waterfall idea is a great idea too, more oxygen means more roots!!

eastcoastmo said:

Yeah that sucks man, but those temps mean you are playing with fire, any warmer and you risk losing your crop to root rot and that shit sucks balls! Can you put a frozen bottle of water in there every day to try and lower temps? Even put in an airstone as well to keep the oxygen up higher... sorry man, I'm not trying to cause you any grief, I just don't want to see your grow go to shit

The waterfall idea is a great idea too, more oxygen means more roots!!

Click to expand...

Ill give the frozen water bottle a go once I get the res set up.

Also, for cutting off the brown roots, how far up should I cut?

Sweet as mate, anything that works is better than nothing!

As for the roots, go all the way up to where the first white shoot is coming out.

So I cut off the browning roots, added 1/4 strength nutes, root mass got huge and they are all white, as of two days ago out of nowhere all the leaves started canoeing (curling upwards) along with feeling very stiff and crumbly at the edges. Nothing changed during that time, pH is at 5.75, i turned the fan off thinking too much air could be drying out the leaves. I raised my lights thinking they may have been too close. No change, in fact it looks like its getting worse. No pics right now but I will add some later.

I have no idea how this could have happened when there has been no change in anything ive done since I added the nutes.

It sounds like heat stress to me mate. What are the temps like in the tent? I had something similar happen when I grew in a tent in summer, my temps got well over 35 celcius and the leaves curled upwards. Keep that fan on mate, if you have sufficient humidity in the tent, the fan circiulates the air. Either way, the fan will help to circulate. Are you in a position to find out what the temp and RH (relative humidity) are?

eastcoastmo said:

It sounds like heat stress to me mate. What are the temps like in the tent? I had something similar happen when I grew in a tent in summer, my temps got well over 35 celcius and the leaves curled upwards. Keep that fan on mate, if you have sufficient humidity in the tent, the fan circiulates the air. Either way, the fan will help to circulate. Are you in a position to find out what the temp and RH (relative humidity) are?

Click to expand...

Ambient temperature in grow area is 76 F

I did some trimming to the plant as you can see, im trying to main line her.

Hmm, damn, it's got me buggered hey. The root mass looks good, temps are good. How's the humidity? I'd stop trimming for a while too, until she's a bit healthier.

eastcoastmo said:

Hmm, damn, it's got me buggered hey. The root mass looks good, temps are good. How's the humidity? I'd stop trimming for a while too, until she's a bit healthier.

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Unfortunately I do not have a hygrometer atm, the air seems to have some moisture in it (slightly more then the ambient moisture of the room). pH also seems good fluctuating between 5.5 and 5.8.

It's really got me puzzled mate, all your parameters sound in check. The only other thing it could be is nute burn/lockout but you're only using 1/4 strength which is far from being too much, hence why it's got me buggered. I hate to suggest it but are you in a position to scrap it and start again?

eastcoastmo said:

Hmm, damn, it's got me buggered hey. The root mass looks good, temps are good. How's the humidity? I'd stop trimming for a while too, until she's a bit healthier.

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mo check this shit out, if you havnt tried its its magic, they sell another product called trichoguard to, im outdoors but pythium & other root/stem rots wiped me out solid for years until i got this stuff, CSIRO scientist makes this gear http://www.biostim.com.au/myco-gold.html

eastcoastmo said:

Hmm, damn, it's got me buggered hey. The root mass looks good, temps are good. How's the humidity? I'd stop trimming for a while too, until she's a bit healthier.

Click to expand...

roots close to the stem lookin a bit brown..im thinkin pythium or other root rot type infection, ive been to hell & back with that shit

That biostim stuff is great hey, I actually know the CSIRO guys that make it lol.
I was thinking root rot or pythium too, the roots looked like they were browning pretty quickly.
@GrapeNut did you try the ice water bottle in the res? 25 celcius is pretty much perfect temp for root rot.