What does this leaf say to you?

So, yellowing and browing around the tips of the leaf... What's causing this?

Keep in mind the plant has never been fertilized, and has been flushed at the first sign of this issue.

The plant in question is 2.5 weeks into veg, and the problem is slowly progessing to higher and higher leaves. They yellow at the tips slowly, the yellowing progresses, then the leaf burns/dries up.

~200w CFL lighting, temps always under 85f.

Watering... Plants are generally watered every 3-4 days, but not until thoroughly dry. Plain tap water.

Thanks everyone.

what about ph

I honestly wish I knew.

pH Testing kit (reagent) coming in the mail soon... Hopefully by this Friday.

Earlier in the grow, the plants leaves were curling downwards (as if overwatered) as well - if that has any significance.

could be alot of things it can be heat stress light stress and or salt build up

Well, considering I'm growing under CFL lighting... And the temperature has never increased past 30c (86f) - and generally stays at around 84f...

The plant was also leeched, and hasn't even been fertilized once (salt?)

I'm at a loss, really.

i think once u get ur ph in check ur prob will be solved
ph is a big factor

Most likely your PH is off. If you are using tap water, it could be a high PH. Try watering in a little lime to the soil while you are waiting on your PH kit. I highly recommend investing in a quality PH pen. Its the most important meter to have as a grower. (TDS meter is next).

Are you sure the soil gets dry? Do the pots feel light when you pick them up? If your soil dont have good drainage then that could lead to overwatering symptoms which is most common problem. Also stir up top half inch of soil till its like sand to get air down to roots. Besides that I would look at water ph first, also letting water sit out for 24hrs to get rid of chlorine and be at RT is helpful to some people.

Thanks for the responses people. I definitely can't wait to get an accurate pH reading.

I've tried adding a bit of calcium Carbonate to the water a few days ago - it seems to have made the problem worse. Perhaps my pH is too high.

Your babies are telling you "Daddy this dirt is bad down here" leaves are only indications as to what's happening below. Perhaps flushing with some distilled water followed by some wonderful appropriate nutes would help .. Ofcourse don't know about the dirt and drainage, important factors to consider before I'd say for sure.

What kind of soil are you using? It sounds as if you are watering appropriately.

If you haven't added any nutrients I would say your soil is too "hot". That does not look at all like a pH issue...though you should know the pH of everything you give your plants and the pH of the soil.

What does the rest of the plant look like? Can you take an entire plant shot? One leaf turning a little yellow isn't uncommon or that big of a deal really...but if it's spreading to the rest of the plant it is.

Alright. Well, as a precaution, I flushed each of their little cups with about half a gallon of water... in place of their watering this work week.

I agree that this does not look like a pH issue (Although the clawing leaves on another plant might say otherwise) but we'll know for sure soon.

I'll update with more pics, and pH results, ASAP.

nitrogen df add a small bit of sugar to the water and water the plant with this mix for 2 weeks

What soil are you using? If its miracle grow it already has nutes in it you have to watch for that with some soils they already have nutes in them!

OK. Quick update... The problem is progressively getting worse. Even after flushing.

The lowest leaves are a very pale yellow, and this chlorosis is starting to creep up into the higher leaves as well. This is looking less and less like a pH issue to me (although I don't doubt that could be out of whack as well)... Alas, there's no pH kit in my mailbox yet - so that reading will have to wait.

Soil is a custom mix that I've used with great success in the past. It's 30% perlite, 30% miracle grow organic choice and 40% bulk organic potting soil. It's sterilized before use, and pasteurized before transplanting to bigger pots.

The pic included is a day 11 seedling.

It's strange... Other seedlings of similar genetics are doing absolutely fine in the exact same conditions - it's just this (and one more) plant that's having issues. And of course, these conditions have grown many other genetics in the past without so much as a single issue...

Looks like they need nitrogen to me. You said you haven't fed them yet at 2.5 weeks? I'd say its about time. After all, how long would you last on just water?

IMO, it's hungry?
I'd remove the dead stuff as it browns.

i agree looks like N def
start feeding
but still make sure ur ph is right

If it's just 2 plants then it's probably strain related...maybe they like to eat more than your others? Hit em with some N and get back to us.

Thanks for the help guys - Yeah... I've got this mental block that prevents me from fertilizing whenever I see burning... Bad experiences with nute burn as a (newer) grower.

I'm repotting them (it's due time anyways, their root balls are filling the entire cup) into a mixture of organic potting soil, mushroom compost and perlite - and I just gave them a quick watering with some nutes at 30% strength.

Let's see how they do in the next couple of days.

Cheers.