THC Bomb In Trouble

TheGreenMidget

TheGreenMidget

Member
I'm a bit of new to growing, and I hope some of you more experienced gardeners can help me out. I've done 2 dirt grows before which weren't unsuccessful, but there were certainly problems. I'm now doing my first hydro grow and I've got a sick plant.

The Problem:
A THC Bomb plant is in week 4 of vegging. Some of the large fan leaves, starting at the bottom of the plant, started to yellow between the veins. That yellow is turning to dead brown spots. Pictures attached.

The Setup:
5 plants vegging (18/6 light cycle) under florescent lights (4ft x4, 2 ft x3, big ass cfl x2). Drip irrigation hydroponics. General Hydroponics nutes (Micro 2.5 ml/gal, Bloom 5 ml/gal, distilled water 3 gal). pH around 5.5-6. Drippers on for 10 min 3 times per day. Plants growning in 4" rockwool cubes inside clay pots filled with Hydroton expanded clay pellets. Temp stays low 70's day and high 60's night.

My Guess:
From what I've found searching the interweb I thing it might be Mg deficiency and the solution seems to be adding a little epsom salt. I'm a little timid to add epsom salt because all 5 plants share the same resevoir and the other 4 are looking fine and I don't want to hurt them by changing anything.

Any thoughts on my situation? Would adding epsom salt hurt the healthy plants? What about misting the leaves with an epsom salt solution? Or am I way off with the Mg deficiency diagnosis?

Thanks for your thoughtful advice to come!
 

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super2200

super2200

Well-Known Member
TheGreenMidget said:
I'm a bit of new to growing, and I hope some of you more experienced gardeners can help me out. I've done 2 dirt grows before which weren't unsuccessful, but there were certainly problems. I'm now doing my first hydro grow and I've got a sick plant.

The Problem:
A THC Bomb plant is in week 4 of vegging. Some of the large fan leaves, starting at the bottom of the plant, started to yellow between the veins. That yellow is turning to dead brown spots. Pictures attached.

The Setup:
5 plants vegging (18/6 light cycle) under florescent lights (4ft x4, 2 ft x3, big ass cfl x2). Drip irrigation hydroponics. General Hydroponics nutes (Micro 2.5 ml/gal, Bloom 5 ml/gal, distilled water 3 gal). pH around 5.5-6. Drippers on for 10 min 3 times per day. Plants growning in 4" rockwool cubes inside clay pots filled with Hydroton expanded clay pellets. Temp stays low 70's day and high 60's night.

My Guess:
From what I've found searching the interweb I thing it might be Mg deficiency and the solution seems to be adding a little epsom salt. I'm a little timid to add epsom salt because all 5 plants share the same resevoir and the other 4 are looking fine and I don't want to hurt them by changing anything.

Any thoughts on my situation? Would adding epsom salt hurt the healthy plants? What about misting the leaves with an epsom salt solution? Or am I way off with the Mg deficiency diagnosis?

Thanks for your thoughtful advice to come!
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Dude for one if your using GH why arent you including the Gro? I dont understand your nute mix. You appear to be using a 3 part mix but only have 2 parts and the mix is off if this is the Flora line by GH Floragro, Floramicro and Florabloom?

I would be doing equal amounts of all 3 at this stage of veg. To me it appears you have not enough n and micro nutes and way too much bloom. I am not a hydro guy so please excuse my blunder if you are spot on and I am giving bad advice but to me they look soon to be crispy and crumbly probably due to low amount of micro compared to amount of bloom your using also no N. Again lets see if someone bashes me for telling you this but I thought I knew the GH line including the advanced and you seem to have a strange mix IMO
 
super2200

super2200

Well-Known Member
TheGreenMidget said:
Typo on the nutes, i'm using micro 5 ml/gal and bloom 10 ml/gal (the 2.5 and 5 was used for first 2 weeks of life).

I'm using the 'lucas formula' (https://www.rollitup.org/hydroponics-aeroponics/4387-lucas-formula.html). Other people seem to have success with this, but if the consensus is that I should use the gro as well I can start doing so.
Click to expand...
Ok I see, and yes it does contain some but I dont get why you would buy it and then not use it. If his tricks are working for you then fine but the nutes come with directions and going outside the instructions is experimenting as I guess its not specifically for weed but if you ask me its best to use all 3 and back off if you think its burning the plants. I would rather go with smaller dose than cutting it out altogether. Its a 3 part for a reason and even the 2 part line the GH puts out includes a Gro and Bloom. If your just starting out I would rather go with the instructions laid out by GH and ease the plants into more and more. Good luck and I would just back off the bloom a bit and add a bit of the gro just to see.
 
super2200

super2200

Well-Known Member
yah looking at the label now I can see that the bloom has 1.5% mag and micro has NONE but the Gro has another .5% therefore if your using the Gro you would be getting the missing Mag and also the Gro includes Bloom nutes so I could say that I dont need the Bloom because the Gro has it as well. Who the hell is Lucas? I would just add the Gro and theres your added Mag instead of salt only 2% N so not too much as the micro I believe has like 5%
 
TheGreenMidget

TheGreenMidget

Member
I bought some Cal-Mag+ and added 2.5ml/gal to my water yesterday. I was unsure of concentration, so I started small. The back of the jug gives a desired range of nutrients for a hydro system and then says what 10 ml/gal of cal-mag plus would add. From back of Cal-Mag+ jug:

Desired:
N: 160-250 ppm
Ca: 160-280 ppm
Mg: 45-75 ppm
Fe: 2-7 ppm

10 ml/gal of Cal-Mag:
N: 53 ppm
Ca: 84 ppm
Mg: 31 ppm
Fe: 2.6 ppm

I don't have a EC meter, so I can't check my resevoir ppm levels, but wouldn't that just give me total ppm and not individal element concentrations?

I'd like to calculate what the elemental concentrations from my GH nutes would be, but they are listed as a %, not a mass or concentration. Is 1.5% the same as 15,000 ppm? So, if I add 15 ml of florabloom, and it has 1.5% Mg, to a 3 gal resevoir do i get 19.8 ppm Mg?

(15,000 ppm)(15 ml) = (x ppm)(11,356 ml) [11,356 ml = 3 gal]
x = 19.8 ppm

Is this the correct way to calculate this? Also, if I got an EC meter is there a way to measure individual ion concentrations or is it just total disolved solids? And what good does knowing TDS do if you don't know individual ion concentrations?

Lastly, I'd like to use the Cal-Mag+ to foiliar feed the one plant that is sick. What kind of concentration should I use for that?
 
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