Bottom leaves drying up, discolored, short roots

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yesimyann

Member
Hey everybody, I'm not sure if this is much of a problem, as I'm pretty new to this, but I could use some help to make sure i can get all the way through the grow.

I am growing a DNA genetics rocklock feminized strand, I believe I'm somewhere over 2 months into the grow, and the plant is about 2 feet tall now, probably a little taller. It looks like its growing fine from the top, perfect new leaves coming out and everything, and quite often, but the bottom leaves dry up a lot and get spots as you can see in the pictures. Also the root system isn't as big as I think it should be, with only two main roots that are longer than an inch (they are probably about 6 inches, see pics) the rest of the roots don't seem to grow any bigger. Besides for that, I have had many problems with pH on this grow, from needing to use pH down every day with my last 2 nute solutions, and now I have to raise the pH almost every day. I wasn't expecting to have to raise pH so I am using baking soda for this (is that even ok?) the nutes I'm using are Botanicare PureBlend Pro grow and Botanicare Liquid Karma. It is on full strength solution also. I have recently run out of nutes too so when I go to buy some more for the next batch, should I get the same thing or different nutes? Ok well any help would be appreciated as to what might be happening, please see pics attatched. Also, the tips of many of the leaves seem to turn brown. Just the very tips, and someone had told me I should just cut these off. I also live in a very dry desert climate so do I need a humidifier or something?
 

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yesimyann

Member
also, i use distilled water from the store for the solution. and am using CFL's and have a fan on, oscillating at all times.
 
satire

satire

Active Member
Are they getting fed through a drip system or a sprayer from underneath? What is the current PH and TDS reading for your res? You also mentioned that you're in a warm climate, do the contents in the res feel warm or cold? If your res temps are too warm, it could be cutting off oxygen to the plant, and inviting bad bacteria. It almost looks like the roots are getting air pruned.
 
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yesimyann

Member
satire said:
Are they getting fed through a drip system or a sprayer from underneath? What is the current PH and TDS reading for your res? You also mentioned that you're in a warm climate, do the contents in the res feel warm or cold? If your res temps are too warm, it could be cutting off oxygen to the plant, and inviting bad bacteria. It almost looks like the roots are getting air pruned.
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It's a drip system, I try to keep the pH as close to 5.8 as possible and I don't have anything to read TDS but the water level is definitely low compared to when I first added water. I'll try to put another couple of gallons of distilled water in tonight to raise the water level and make it not so concentrated, but the res has always felt cold. How do you stop from ''air pruning?'' Res temp I'd say has to be under 78. I have a 14 inch air stone to bubble the water and its still looking like its in good shape.
 
satire

satire

Active Member
I would stick with your plan and just top off with some plain water and see how things go from there. The leaves are dark, which indicates they have plenty of nitrogen, but I'm just surprised that a plant that size can survive with such a small root system. A TDS meter to read EC/PPM will be vital in your growing. As far as air pruning, I don't think that's really what's going on, but that's what it looks like is happening to the roots. Are there any major air gaps between the net pot and the rubbermaid container? If a bunch of air/light is getting in there, that will not make the roots very happy. How often are you feeding them, or is it a constant drip?
 
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yesimyann

Member
satire said:
I would stick with your plan and just top off with some plain water and see how things go from there. The leaves are dark, which indicates they have plenty of nitrogen, but I'm just surprised that a plant that size can survive with such a small root system. A TDS meter to read EC/PPM will be vital in your growing. As far as air pruning, I don't think that's really what's going on, but that's what it looks like is happening to the roots. Are there any major air gaps between the net pot and the rubbermaid container? If a bunch of air/light is getting in there, that will not make the roots very happy. How often are you feeding them, or is it a constant drip?
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The rubbermaid is pretty big, I think you may be on to it and thats what the problem is. There are about 10 inches from the top of the water to the bottom of the net pot. I have a lot smaller bucket I could put them back in to so that roots would be mostly submerged at all times, and I have the bubbler 24/7 so would this be recommended? The plants are fed on a drip for about 30 minutes 3 times a day, at 5.30, noon, and 6.30, with lights on at 5am and off at 11pm. I will pick up a TDS meter tomorrow, what should the reading be when the nutes are on full strength?
 
satire

satire

Active Member
It's ok for the roots to be suspended in the air, I actually grow using aeroponics, so it's perfectly fine for the roots to dangle. I guess it just looks like there isn't enough humidity inside the rubbermaid for the roots to venture out of the net pot and down into the water below, which is what should be happening in a DWC setup. In other words, it appears that there is either too much light, or not enough humidity inside for the roots to grow. Would it be possible to increase the number of feedings, so you could water for like 3 minutes on, and 5-10 minutes off? If it's not humid enough in the tub, then the roots that should be growing out of the pot could be drying out and dying. When the roots leave the pot they have nothing keeping them moist except for the humidity, and if they have to wait over 10 hours for more water, that might be killing them.
Once you get your new meter, I would look on bottle of nutes that you're using to see how much you should feed. Always start at about half strength, and go from there. If you properly mix the water and nutes, you should need to use very little PH up/down. Given the size of your plants, you'll want to have an EC of around 1.5, but it all depends on the strain and many other factors, but 1.5 is a good place to start.
 
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yesimyann

Member
satire said:
It's ok for the roots to be suspended in the air, I actually grow using aeroponics, so it's perfectly fine for the roots to dangle. I guess it just looks like there isn't enough humidity inside the rubbermaid for the roots to venture out of the net pot and down into the water below, which is what should be happening in a DWC setup. In other words, it appears that there is either too much light, or not enough humidity inside for the roots to grow. Would it be possible to increase the number of feedings, so you could water for like 3 minutes on, and 5-10 minutes off? If it's not humid enough in the tub, then the roots that should be growing out of the pot could be drying out and dying. When the roots leave the pot they have nothing keeping them moist except for the humidity, and if they have to wait over 10 hours for more water, that might be killing them.
Once you get your new meter, I would look on bottle of nutes that you're using to see how much you should feed. Always start at about half strength, and go from there. If you properly mix the water and nutes, you should need to use very little PH up/down. Given the size of your plants, you'll want to have an EC of around 1.5, but it all depends on the strain and many other factors, but 1.5 is a good place to start.
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Alright. What can you do to increase humidity in the DWC? In the meantime I've switched to the smaller system, here is the basic kit I started out with, http://www.stealthhydroponics.com/product.php?xProd=47&xSec=53, so its in a 4 gallon bucket now and the bottom of the net pot is submerged in the water. Im going to cover the other holes so there is no other air coming in, since I only have one plant growing. As of now, I don't have a timer that can do waterings for under 30 minutes, but I will look for one tomorrow at the hydro store. But otherwise, its ok for the bottom of the netpot to be submerged in the nute solution as long as a bubbler is going on at all times?
 
satire

satire

Active Member
If your roots are submerged, you won't need to worry about watering anymore. The bubbler you already have will be necessary to deliver oxygen to the roots, so you should be fine there. You basically want it to look something like this:View attachment 1106636
I think the most simple solution will to be what you've already done, which is fully submerge the pot into the res, and give it a few days to see if the root will start to grow naturally. Then if you want to raise the net pot back up, then you can get a new timer that will allow for more frequent feedings.
 
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yesimyann

Member
Alright, thanks a lot. I'll try this out and see what happens over the next few days and hope for the best. I'll post back later to let you know how things are going. Again, thanks a ton for the tips.
 
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yesimyann

Member
So I got the TDS meter, and I adjusted everything to what you said. The solution was at 1600 ppm, and I took out a lot and replaced it with some distilled water and brought it down to about 778 ppm, which is about 1.5 from what conversion chart I could find. I'm bringing in my pH meter on tuesday to have re-calibrated to make sure it is still right too. The current pH is 6.0. I've bought more nutes and a better bubbler so I hope everything pops back in to shape. The top of the plant is still shooting up fast, but the two lowest leaves have turned a yellowish, I'll have to see if this goes away with the correct ppm now. Since submerging the roots, they have begun to grow very well and are shooting out of the net pot pretty well now. I'm gonna try and clip some clones tomorrow morning and see if I can get them started out well.
 
satire

satire

Active Member
I'm very glad to hear that the root situation is getting fixed. Sounds like it was definitely an issue of moisture in the root system, they were just getting too dried out and dying. If you decide to go back to a drip, you'd be better off just letting it run constantly. If the yellowing of the leaves continues, you can start to slowly increase the PPM. As your plants grow they will require more nutes to feed more branches, and depending on the strain, they can get very hungry. If that yellowing starts to get worse, increase to around 1100 PPM and see if that resolves it. Typically you want to have an EC range between 1.6 and 2.3 for a healthy plant, or 1100 and 1600 PPM.
 
kingofqueen

kingofqueen

Well-Known Member
I,m no dwc pro but I have experimented with success on tomatoes . 10 inches sounds like too much of a gap .I always keep my water level about 1 -2 inches from the net pot . Also you mentioned baking soda , It has alot of salts in it not good . Just use reg ph up and down kit.
My tomatoe roots were long ( about 12-16 inches) and nice and white .I only had trouble when i moved it outside the higher temp made my roots brown but hell I run that thing for 4 months it grew to 6 ft tall massive hand sized leaves .

(edit) to increase humidity run lower dose on fert and cycle your water contantly Hydroton doesnt hold moisture for long. Is that your media ? Your probaly drying your roots out inbetween water cycles and with such a big gap condensation isnt forming . Cycle your pump more often or constantly and raise your res level to 2 in from net pot .
 
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yesimyann

Member
satire said:
I'm very glad to hear that the root situation is getting fixed. Sounds like it was definitely an issue of moisture in the root system, they were just getting too dried out and dying. If you decide to go back to a drip, you'd be better off just letting it run constantly. If the yellowing of the leaves continues, you can start to slowly increase the PPM. As your plants grow they will require more nutes to feed more branches, and depending on the strain, they can get very hungry. If that yellowing starts to get worse, increase to around 1100 PPM and see if that resolves it. Typically you want to have an EC range between 1.6 and 2.3 for a healthy plant, or 1100 and 1600 PPM.
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Will do. So far its just the bottom 2 main leaves which are pretty big sized that have gotten yellow and brown. haven't noticed any more problems with any other parts of the plant, but have raised the ppm into the 800's. Roots still looking nice and getting longer. I just started 4 clones today with a new Gel that i bought (Rootech) and I did 2 in rootech and 2 in vitagrow to see which ones do better.
 
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yesimyann

Member
kingofqueen said:
I,m no dwc pro but I have experimented with success on tomatoes . 10 inches sounds like too much of a gap .I always keep my water level about 1 -2 inches from the net pot . Also you mentioned baking soda , It has alot of salts in it not good . Just use reg ph up and down kit.
My tomatoe roots were long ( about 12-16 inches) and nice and white .I only had trouble when i moved it outside the higher temp made my roots brown but hell I run that thing for 4 months it grew to 6 ft tall massive hand sized leaves .

(edit) to increase humidity run lower dose on fert and cycle your water contantly Hydroton doesnt hold moisture for long. Is that your media ? Your probaly drying your roots out inbetween water cycles and with such a big gap condensation isnt forming . Cycle your pump more often or constantly and raise your res level to 2 in from net pot .
Click to expand...
Thanks, I actually have the plant in gro-dan and then hydroton for a little more support. the bottom of the net pot is sitting in the water about an inch or so to ensure constant moisture, and there is a big bubbler going. I did set my above watering cycle to be about every 2 hours for 30 minutes just to make sure since i dont have a digital system yet. But Im done with baking soda, I have a General Hydroponics dry pH down that I've always used, although am not positive how god the stuff is, and if i need pH up again, Ill be buying some during the week. Thanks
 
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