Help! - Yellowing leaves!

[kennbuds]

Leaves started turning yellow starting at the edges about 24 hours ago. They have started showing slight yellowing on the edges and has quickly spread to most of the leaf.

Conditions:
Vegging under 4-42w CFL & 1-125w CFL. All are 6500k and about 2-4 inches from plant tops. Temps from 78-85 degrees, usually around 81. No ferts yet. Water is PH balanced to about 6.8 and plants are watered about every day. Currently in 4 inch pots for vegging. Soil was checked last week at around 6.7. Soil is professional grade from a local nursery. It does have nutes, but they were very minimal (.08, .02,.05). Growth has been great up until now.

Please help!

kennbuds Reviewed by kennbuds on 05-06-2008. Help! - Yellowing leaves! Leaves started turning yellow starting at the edges about 24 hours ago. They have started showing slight yellowing on the edges and has quickly spread to most of the leaf. Conditions: Vegging under 4-42w CFL & 1-125w CFL. All are 6500k and about 2-4 inches from plant tops. Temps from 78-85 degrees, usually around 81. No ferts yet. Water is PH balanced to about 6.8 and plants are watered about every day. Currently in 4 inch pots for vegging. Soil was checked last week at around 6.7. Rating: 5

[stinkyattic]

How tall are your plants, and how many nodes?
Does the soil stay quite wet between waterings? It should dry a bit.

Given that set of info, it sounds likely that they are just hungry. Pics would be helpful though. If the tips show scorch, flsuh the plants well with plain water at pH 6.8 and then give a weak feeding of a 'grow' fert with micros, assuming that they have at least 4 sets of adult leaves.

[kennbuds]

No it is only an inch tall on second node - too early for nutes.

I thought it might be overwatering as I soak them once a day. Pics should have been attached. Let me try attaching again. Let me know what you think.

[stinkyattic]

I think you are using pre-ferted soil. Those nute levels look okay but the plants tell a different story! I would flush, or better yet, start fresh with a different soil meant for seedlings. Try running a couple bagseeds to 3 or 4 nodes to test your setup before using good seeds. As for overwatering, that might be a problem too.
How are you adjusting the pH of your water? Where does teh water come from? Have you tried just running plain unadjusted tap water? That looks like burn. I wonder if it's from your pH adjustment, the soil, or something (sodium possibly) in your water? Very odd, because 'on paper' you should be fine with those specs!

[daihashi]

I'm willing to bet Stinky hit the nail on the head. Every nursery I went to sold me ferted soil even though I specifically told them I needed a nutrient free soil.

I would say get a peat puck and try sprouting a seed in there and grow it out. See if you still have the same problem.

You should be able to grow a seedling in a peat puck to a few nodes (3-4); at which point it should be able to handled a *light* pre-ferted soil in the instance you cannot find a nice hummus based soil mix.. or if not hummus then peat soil mix for your baby seedlings.

[kennbuds]

The only thing I could find was a soil with very "minimal" nutes - exactly (.09 . 04 .06). I am using filtered water with a minimum of 24 hour before use. I adjust the filtered water with PH-up and PH-down - made for spas/pools. I just checked the soil (runoff method) and water and it is in between 6.5 and 7.0. I'm going to try to go back to regular tap water - PH adjusted.

Peat puck sounds like a good idea for the next grow but I wouldnt mind saving these ones. I have one plant of a different strain (feminized Fire Hydrant) that is doing rather well under the same conditions (soil, water, and lighting). It's showing minimal signs of yellowing but is not "full on" like the other two.

Thanks for any feedback.

[stinkyattic]

Okay. We may be closer to your problem source! Pool pH up may quite well be sodium hydroxide. I'm not sure, but that pattern of damage just makes me think salting for some reason. It's a hunch haha. Plain unadjusted tap water is much safer than pool chems on plants. The hydro ones are meant to be safe for plants. You don't need filtered water. Just plain ol tap water is almost ALWAYS good to use in dirt.

[kennbuds]

So you suggest regular un balanced tap water might help?

Before - I used small amounts of lime to raise the ph of the soil when I tested it 5.7. It currently is (6.8).

How should I adjust ph in my water if I shouldn't use "PH up & down"?

[kennbuds]

My tap water just tested at 7.8. Should I use this water to flush the plants rather than the 6.8 ph balanced one?

[stinkyattic]

For now, I would try bringing it down with apple cider vinegar instead of your pool chems, and see if you can pick up proper plant chems asap. Cider vinegar isn't the IDEAL pH down, but as emergency pH adjustments go, you can do a lot worse, and there is something in it that the soil microbes acutally like- I'm not up on my mycos though so I can't explain it. lol.
What does the label on your pool chems say? I am interested in the actual chemical composition of them.