Identifying a Problem Caught Early

Hello!

I was wondering if anyone could give me a second opinion about a plant health problem that I caught early. I just want to make sure that I have the issue identified.

I believe this Jock Horror is over fertilized. Small brown spots appear on the older leaves and/or the leaf tips (older leaves) start to turn brown. The center portions of the leaves seem lighter than they should be. Also the edges are curling up slightly. These pics were taken last night. Befor anyone mentions it I know the leaf was touching the nute solution during the watering cycle. I fixed that

*I know the pH was off (probably high 6's) because I was dumb enough to do this hydroponically and only use the color strips. I got a meter and set the solution to 5.5 yesterday.

*The EC was probably too high. Instead of starting at 25% and working my way up I was at the "mild vegetative growth" levels from the "General Hydroponics" bottles which come to about 750. While changing the pH I diluted it down to about 380 or so.

I fixed the pH and diluted the nute solution like I mentioned. I used the distilled water (pH adjusted) that I diluted with to flush the rockwool that I use for flood and drain hydro growing.

It can't be over watering since hydro in rockwool is supposed to be impossible to over water (I do one 30 min flood and drain cycle every four hours). It is not heat since I can put my hand under the light at plant level for more than a minute with no problems.

This is my first grow and I am paranoid as hell! Thanks!

well, the tacoing of the leaves suggests too much heat (though not much)

i see nothing to worry about and problem handled. judging by your describtion.

the new growth looks fine too, sturdy healthy plant with perhaps minor ph problems in the past.

if you look at my pics, i had the same problem, it just went away with new growth, dont worry, its a weed, your goign to have to do alot to kill it!

Thanks both of you! It's nice having my suspicions confirmed. Hopefully from here I won't see more brown.

New growth looks good. The brown stuff looks like a calcium deficiency or maybe a lockout from too high ppm. Seems to be cured.
Most nutes are formulated for tap water which usually has quite a bit of calcium. The distilled water you were using probably caused the deficiency.
Like SSO said, the curling is probably heat related.
Good luck,
Fred

fred flintstoned said:

New growth looks good. The brown stuff looks like a calcium deficiency or maybe a lockout from too high ppm. Seems to be cured.
Most nutes are formulated for tap water which usually has quite a bit of calcium. The distilled water you were using probably caused the deficiency.
Like SSO said, the curling is probably heat related.
Good luck,
Fred

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Good advice, but don't rule out magnesium deficiency. 1/4 tsp. epsom salt dissolved in water and added to your next water cycle couldn't hurt, but too much will.

I'm having a similar problem at the minute I think mine is due to nute burn as well. back to just water for a week or two for my baby

Thanks Fred and tiny. I don't think that neut deficiency is the direct cause though since the General Hydroponics micro is supposed to have calcium and such. I have not seen any new spots or brown tips since i diluted and properly pH'd. I was seeing daily slow progression on the oldest leaves and it seems to have stopped. I guess pH meters are a must for hydroponics work. What I thought was 5.5 was actually more like 6.5. Ill post new pic's if anyone wants to see it. What helped for me is the realization that the plants may be absorbing nutrients even if they do not need them (I need to read about this). They have internal garbage dumps for waste neuts, but when those get full they keep bringing stuff in which gets toxic. I think what I will do from here is check pH and TDS every day and graph the plant use. If TDS decreases I will add slightly more until it stops going down. Hopefully that is the point where the plant is growing fastest and using everything you give it. Thanks everyone! Now to figure out if I need to worry about algae in my rockwool.