What's Wrong?

This is my second grow and I learned a lot from the first time around. I'm growing 3 plants under about 600 watts of CFLs. 2 of my plants have been vegging for about 6 weeks now and the other only about 3.5. Up until last night everything seemed to be going as planned. I noticed a couple leaves on each of the lagers plants are starting to yellow. Any idea what is causing this?



Age: Approx 6 weeks
Soil: Organic potting soil with some perlite added
Lights: Approx 600 watts of CFL
Light Schedule: 20/4
PH level: 6.2-.6.7
Water: Tap water that I let sit for a few days
Nutes: Fox Farm Trio (Just BB and BG for now every other watering)

I haven't given the plants nutes in about a week and when I did the highest dose I've given them is 50% of the recommended. If anyone has any feed back it would be greatly appreciated, thanks guys.

At 6 weeks maybe root bound? Using something other then daylight bulbs?
Your method seems
fine so this is a good question you posted.
Sometimes even a very healthy plant will throw off a leaf or two
here and there through veg so I wouldn't worry about it unless
the yellowing spreads fast and not only periodically.

How are you testing your PH?

feed it an she will be fine looks like she wants some N

Alright cool, thanks for the quick feed back guys. Today is watering day (with nutes) so hopefully that will help. I'm gonna step the dosage to about 100%. I've just been cautious cause I wont wanna burn them.

I've been using a mixed spectrum of about 3:1 (6500k to 2700k). I have them in 15L (4gal) containers and was hoping that would be big enough for the rest of the grow. I'm switching them to 12/12 on Wednesday.

This is what I'm using to test the PH http://www.ebay.com/itm/General-Hydroponics-pH-Control-Kit-8-oz-pH-UP-8-oz-pH-DOWN-1-oz-indicator-/141177350998

Here are what the 2 plants look like...

Are you testing the water with or without nutrients? Are you testing runoff?

Peat based soils are very acidic, so be sure to test the soil, or at a minimum the runoff. Most leaf necrosis is caused by lockout due to PH.

I test it before I give it to the plants (with the nutes if it's nutes day, without if not obviously). I haven't been testing the run off or soil because there hasn't seemed to be a problem until now but I'll defiantly check it out.

Im sorry, but soil testing for ph is retarded. As long as you don't add just normal tap water or anything inorganic like miracle grow etc. you will be fine. Im sure ill be flamed for this but flush your soil. Stop what you are currently doing and add fish emulsion, Epsom salts, and a very small amount of non sulfur molasis in small doses as a foliar spray. You will see results.

Calm down about ph. stop using tap water, or at least filter it.

tripwire911 said:

Im sorry, but soil testing for ph is retarded. As long as you don't add just normal tap water or anything inorganic like miracle grow etc. you will be fine. Im sure ill be flamed for this but flush your soil. Stop what you are currently doing and add fish emulsion, Epsom salts, and a very small amount of non sulfur molasis in small doses as a foliar spray. You will see results.

Calm down about ph. stop using tap water, or at least filter it.

Click to expand...

Agreed about the tap water for sure. If you are using tap you might want to add some organic molasses (unsulfered) to your nutrient mix. Keeps Calcium and Magnesium deficiencies down. Wholesome's Organic Molasses in the green lable.. If you can find the stuff with the rabbit on the front it's the bomb for this too (green lable as well). They have found that the Calcium in tap water is to large to be absorbed by plants and can actually put a "cast" around your roots...leading to big problems. I am pretty sure that you have a Magnesium Deficiency, But I'm no doctor....I just play one on tv.