yellowing leaves in Hydro setup

MrZee said:

Yellowing leaves on the bottom is a sign of Mg deficiency, but it's also the sign of a few other issues, like nute burn. Is there anyway you can post pics?

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michmed said:

The story of my life....
About a week ago I transplanted clones in rockwool cubes into an Ebb & Gro system with 24 plants.

The 24 plants are prollly pretty close together just an inch larger than the 9.5 inch pots, I screwed up the spacing. So the 24 plants are in a 5' x 4' rectangle.

I have two 1,000W HPS lights on 18 hours/day. they are currently 26 inches above the hydroton and 20 inches above my six inch plants.

The room has been getting too hot 100.1 degrees last night (I have set the lights to be on during the cooler night and off during the day (Noon - 6p)

Also my pH was a bit over 7 for the first 3-5 days I've since lowered it to 5.4

Now my leaves are turning yellow on the bottom....

wondering if it's the heat, pH, or some other thing

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michmed said:

I didn't turn off the HPS lights and they were insanely orange colored, I tried to balance using Picasa

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BquamB said:

Wow 1000w Hps for those little guys? I think that the lights might be a little too strong at this stage and the ventalation's improper... Probably being 100.1 Deg is having some effect on the plants.

Are you Adding any nutrients to the Soil and what type of soil were they planted in? my first grow had a similar effect, Wasn't with HPS (i wish it was) but Once the Temp went to 75-85deg it was Happy and the Ph should be no lower that 6-6.5 you're Ph is too strong for the little things at this stage of growing, I may be new but I've read enough to know 5.4 is too harsh to grow in. 7 is cutting it thin as well... try 6-6.5.

Also How's your Venting and Air Circulation? Buy a Cheap CPU heatsink and a few Fans or an Industrial low blow setting fan to help that hot air keep moving. With that many plants, they'll need a continuous flow of fresh fresh air.

Subscribed, good luck. Keep us posted!

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BquamB said:

Okay, The fan shouldnt be a problem (can't see why it would be unless blowing right on the little guys) What setting is the Fan on? Better be Low unless its a large grow room.

Also the PH is too low, Aim for 6-6.5 I've read that anything lower, the plants could be growing but not at the optimal rate.

No nutes have been added to date? You know the Dirt Concentration? Can you take a pic or list its Specs and properties (soil) ?

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michmed said:

OH and once again Hydro no dirt....

Yes I used transplant when moved Monday last week and then added 100ppm Grow on Friday

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