Leaves turning dry (crispy) and curving downward

[isaackei]

First of all, thank you everyone who come in here and have a look or even try to help me (I am not a native English speaker please forgive me with my English).

I am the first time grow any plants in my life and I have three success and healty plants untill yesterday. One of the plants get sick (you can see from the picture).
I am following ‘Foxfarm’ fertilizer schedule for all three of them. After fertilze them and I leave. The plant actually react so fast just after one night, and the next morning i see this happen. all the leaves (top part) get very dry and crispy, they just look like ’dehydration’. and I check the bottom of my pot and I can see a 'swimming pool' in my flowerpot plate (a plate that hold extra water from the pot).

I do some research of what happen but no idea.
And i make assumtion (could be wrong) for what happen.
multiple factor that cause this. one could be the nutrition water at the bottom drown part of the root, and those water act like salt water, instead of the root get water from it. it actually sucking water from the root. so the plant react like underwatering cause the root is losing water. the leaves dry from top half of the plants and the bottom half of the leaves are still freash.
Or, the plant is highly Nitrogen Toxicity.

i try to clean the soil and check the root but it is hard to do so for the plants grow in soil, so i cannot see how the root is going on.

I try to recover it but even i flush the soil, it doen't help, now the plants can be consider as dead.

ow one more thing, is it normal to see springtall (some kind of bug) in the soil?

My setup:
a LED light with 600W (far enough from the plant)
a grow tent (big enought for those three plant)
fertilizer 'Foxfarm' whole setup
i use soil for growing.
and fan for intake and fan for outtake.

I am very appriciate for any of you to read my shit English and thank you verymuch.

[isaackei]

And my another plants is looking health but I know it get too much nutrition is it?????? beacuse the stem are so long

[Mr.furley]

Welcome isaackei,
can you take a couple of pictures in natural light?
what is you Ph levels going in and coming out of the pot?
how far from the plant is that light?

[isaackei]

thank you for your reply. i just post some picture of the sick plant.
i didn't record the PH coming out of the pot, but i do test it once before, it is around PH 5.0 i think

[Mr.furley]

Your ph coming out needs to be at 6.5

[isaackei]

here some picture of the sick plant, i cannot recover it so i clean some soil to see the root. those leaves are so dry that some of it are even break.

[Mr.furley]

This plant looks wind burnt and overwatered.

[isaackei]

here is one of my health plant, as a reference, i use those clone cube. this type of seed is call ' Big bag' is a short plant, but i thing it get to much nutrition and so it grow too long of the stem. and the "thing" (i don't know how it call in English) for PH rise and drop is for Fish. so I think it will be ok.

every time i mix up my fertilizer, the PH will be 4.5, so I need to use a lot of those 'thing' to rise till PH=6.0 to 6.5.

normal fresh water in my country is 7.5-8.0, so i drop it to 6.5 for just simple water those plant if i not using fertilizer.

[Mr.furley]

This plant does look alot healthier then your other, plant with long stems are usually from Lights being to far away from the plant how far do you have you led light?
I don't know about the fish Ph up and down, remember to only add up or down and never the two together, you should check your Ph after you mix nutrients and adjust then only.

[isaackei]

Thank you Mr.furley, thank you very much for your reply.
The distance between the light and the top leaves is aroung 50cm = 19.6 in =1.64 ft.

[Mr.furley]

I don't use led but I hear they need to be a little higher then most lights, what kind of light is it and what distance does the manufacturer actually recommend?

[NebulaHaze]

In addition to what Mr.furley said (I also recommend raising the LED light a few inches to see if that helps), what are your watering practices, and did anything different happen right before you started seeing symptoms on the one plant? Is there any difference between the healthy and unhealthy plants as far as you can tell?

[isaackei]

Thank you NebulaHaze.
Both healthy and unhealthy plants were germinated in same day and i treat them no difference. by far, the only difference between them are the soil I used are difference. the soil for healthy plants have a good reaction with water. This soil are very easy to be wet when i water it and can store most of the water.
But the unhealthy one's soil are very light weight, when i water it, the soil tends to float on the water. it looks like when you pull water into a cup with milk powder, and the water and powder doesn't mix. just like that. and soil does not like to store water.
on that day, i wet the soil completely, because the soil doesn't like to store water, so many water had came out from the bottom and i did not clean that away. and so it happened.

[NebulaHaze]

It sounds like you've discovered the problem. Poor soil and poor watering practices (like letting the plant sit in runoff water) could definitely cause the symptoms you see. You want to remove runoff not long after it comes out the bottom. Roots sitting in water starves them of oxygen (and sick roots can cause all types of weird symptoms from leaf curling to spots to deficiencies).

Is it possible to transplant the sick plant to better soil?

[isaackei]

it is not possible to transplant the sick plant to new soil, unlike water base, plants roots grows amost everywhere in the soil and it is very difficult to separate them. it end up no cure so far for mine plants.