Need Help Identifying a Symptom

Stay here · Nov 29, 2021

Hey guys, I’d appreciate if you could help me identify the symptoms that are going on with my plants. The leaves are turning down and red and some are just drying and falling. I am attaching some photos. The environment is as follows:
day temp 81-82 degrees With humidity around 55-56
night temp 73-74 degrees with humidity around 56-59
Led lights at 1000 full power at 2.5 feet above the canopy.
The grow method is SOG in 6x6 Rockwool
feeding method is drip system
nutrients are HGV notes and nothing else
ph 5.8
ppm 1400
750 mil feed/water for each cube every other day
3 times feed and then flush with 5.8 clean water with 200 ppm.
Runoff 5.9
end of 2nd week of flowering cycle.
Thank you in advance for your help.

AKgrow · Nov 29, 2021

Disclaimer, I don't grow hydro or on that scale. Looking at all the info provided, I think your ppm is too high and probably causing lockout.

Aqua Man · Nov 29, 2021

What are you spraying them with?

Typ of lighting? Mh?

Size of cubes? Runoff numbers? Kinda feel your not watering nearly enough but if your in RW this is the man you wanna talk to if he had time.

@Dirtbag

Dirtbag · Nov 29, 2021

Should be feeding those things like 8-10 times per day with half that amount of food.

I'd bet those blocks are pickled saltier than a Ritz cracker. Clear signs of nutrient toxicity.

Aqua Man · Nov 30, 2021

Dirtbag said:
Should be feeding those things like 8-10 times per day with half that amount of food.

I'd bet those blocks are pickled saltier than a Ritz cracker. Clear signs of nutrient toxicity.

Thanks brother... I was sure that was it but yeah not even dunked my feet in RW yet and knew you'd have the answer as usual.

Stay here · Nov 30, 2021

:( yes guys, I think so too. I just flushed one of them with clean ph 5.7 water. The ph of the runoff came to 5.8, but the ppm was 2200, wow. So as soon as the lights are on, I will flush them with RO water and 2 mil of Revive. I hope this will clear all the salts and what not from them. Dirtbag, how would I feed them multiple times? Should I give them some food, then wait couple of hours, then some more, etc? Thank you guys.

Dirtbag · Nov 30, 2021

Stay here said:
:( yes guys, I think so too. I just flushed one of them with clean ph 5.7 water. The ph of the runoff came to 5.8, but the ppm was 2200, wow. So as soon as the lights are on, I will flush them with RO water and 2 mil of Revive. I hope this will clear all the salts and what not from them. Dirtbag, how would I feed them multiple times? Should I give them some food, then wait couple of hours, then some more, etc? Thank you guys.

Do you have automated irrigation on a timer?

Aqua Man · Nov 30, 2021

Of your going to flush then flush the hell out of them and run a light feed after. So many times I see toxicity turn into deficiency. Remember they may be overfed now but they still need nutrients after flushing.

ComfortablyNumb · Nov 30, 2021

I do not grow hydro, but I can look at your crop and with little effort, I can see the 'stages' your plants have been thru from not enough to waaay too much and back again and even then a cycle back towards overfeeding. This is a great sign that you are feeding too much at a time and its flushed by the time the plant needs it. Personally, I would mix my feed 50% weaker and feed twice as often. Or even more.

Stay here · Nov 30, 2021

Dirtbag said:
Do you have automated irrigation on a timer?

Yes, i have an automated drip irrigation system with a timer. I give each 6x6 cube 750 mil.

Stay here · Nov 30, 2021

Aqua Man said:
Of your going to flush then flush the hell out of them and run a light feed after. So many times I see toxicity turn into deficiency. Remember they may be overfed now but they still need nutrients after flushing.

Man, I wish I stack to my tested nutrients. As i said, this time i chose to go with HGV nutes. I spoke with the manufacturer several times and each time they insisted I feed from the start to finish with 1500 ppm and not give any additives, so I did as they recommended. I have 100 gallon tank for 500 6x6 cubes which comes to roughly 750mil for each. Each time I do see a good runoff as well.

Stay here · Nov 30, 2021

ComfortablyNumb said:
I do not grow hydro, but I can look at your crop and with little effort, I can see the 'stages' your plants have been thru from not enough to waaay too much and back again and even then a cycle back towards overfeeding. This is a great sign that you are feeding too much at a time and its flushed by the time the plant needs it. Personally, I would mix my feed 50% weaker and feed twice as often. Or even more.

Yes, I think you are right. I feed them 3 times, then water once. I feed them every other day, but If I did what you say, feeding every day, wouldn’t that be too much moisture for the Rockwool?

ComfortablyNumb · Nov 30, 2021

Stay here said:
Yes, I think you are right. I feed them 3 times, then water once. I feed them every other day, but If I did what you say, feeding every day, wouldn’t that be too much moisture for the Rockwool?

Rockwool does not care about moisture. The roots will still have the needed O2 and that's the important part.

ComfortablyNumb · Nov 30, 2021

Don't do it my way just because, listen to @Dirtbag . He is the Rockwool Man.

Aqua Man · Nov 30, 2021

I don't think 1.5 is ridiculous depending on what's in it and the ratios. Specifically nitrogen is usually what we base our observations on since its easy to spot both to and deficiency.

It's your fertigation frequency and volume that need adjusting.

The reason is your getting a buildup of nutrients and your block is dying out to much between watering. This makes the ph swing, messes with nutrient availability because of that and the salinity will effect uptake of both water and nutrients on top of drought stress.

The goal is to keep things stable and the best way to do so is to adjust the frequency and volume of your feeding.

I'm not the one to talk about where they should be but I can promise you it will make a world of difference and is the biggest reason for the issues you see 100%.

Stay here · Nov 30, 2021

Dirtbag said:
Do you have automated irrigation on a timer?

Brother Dirtbag. Thank you for your advice. I am new to Rockwool so this is all new to me. I feed each 6x6 cube 750mil. I’d like to follow your suggestion and feed them multiple times. I have 100 gallon tank and 500 plants. Should I start feeding them an hour after the lights come on and stop an hour before dark? Also, I’d like to feed them about every hour and give them 100mil each time. My plants are small since I use SOG method. Also, should I flush them with clean water after they’ve been fed 3 cycles (300 gallon) continuously? As soon as the lights are on, I am going to flush them with RO water and 2 mil of Revive. I plan to use twice the amount I usually give them, or use 200 gallons to flush them clean, then will go ahead and feed them with half strength. I appreciate your help. Thank you.

Dirtbag · Nov 30, 2021

I'm not sure what revive is, but I'd be careful with RO water. Rockwool is typically easy to flush out with even just nutrient solution.
And yeah something like 8 small shots of water through the day is ideal, but in your case I think you'd be best with 4 or 5 feedings per day of about 150-200ml each or so. You want to start getting runoff on the second or third shot of water.
What comfortablynumb said is true, rockwool should be kept saturated, or close to it. Don't let it dry out more than 30% or so.

Stay here · Nov 30, 2021

Dirtbag said:
I'm not sure what revive is, but I'd be careful with RO water. Rockwool is typically easy to flush out with even just nutrient solution.
And yeah something like 8 small shots of water through the day is ideal, but in your case I think you'd be best with 4 or 5 feedings per day of about 150-200ml each or so. You want to start getting runoff on the second or third shot of water.
What comfortablynumb said is true, rockwool should be kept saturated, or close to it. Don't let it dry out more than 30% or so.

@Dirtbag I truly appreciate your expert advice. Yes, I plan on feeding them in probably 4 increments. The lights come on at 7:15AM. 1st feed of 180 mil each at 8:00am, 2nd feed of the same at 11:00am, 3rd feed at 2:00pm, 4th feed at 5:00pm. Two hours before the lights are out.
Should I do this non-stop, every day? Also, should I flush them after 3 feed cycles? Thank you.

tobh · Nov 30, 2021

i'll throw some additional thoughts in here as well.

I wouldn't flush rockwool with straight pH'ed water. That's an easy way to shock the hell out of the plants and cause an osmotic condition (i believe it's called) where the cells suddenly uptake a shit ton of water and explode. Especially with how high the EC is in the media.

A mild nutrient solution or even full strength at high volume (3x - 4x volume of media) should suffice to get you back to where output is the same as input. Once you're back to a state of homestasis, then set your schedule accordingly. @Dirtbag covered what you're after. There are a few schools of thought in regards to fertigating rockwool, and it looks like you're following one which is less frequent, higher volumes of solution.

Given the size of your plants though, the root mass has to be substantial and they're drinking much more than you're giving so you need to either bump up the number of times you're fertigating or do as DB said and do smaller shots, more frequently throughout the day. Both will give similar results but both also demand that you increase the number of fertigation events, period.

tobh · Nov 30, 2021

180ml each is not nearly enough solution. You need upwards of 200 - 300ml each per event. Do this throughout the day, every day at 2 hour intervals give or take.

Only do maintenance flushes if you have good reason to, not just because it seems like the right thing to do. For instance, I only do a maintenance flush if (a) a timer fucks up (b) an event is missed because of some other circumstance (c) right before flip or (d) the runoff EC is off somehow. Otherwise, it's regularly scheduled programming.

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