Please diagnose my plant problem.

blackmetal19 said:

About 5 days ago I switched from 18/6 cycle to 24 hours. Then about 2 days ago the temperature in the area got to just over 90 degrees F, which I know is way too hot. It stayed this way for maybe 12 hours. The next day one of my plants started looking very bad, Plant A in the pics, with yellowing around the edges. I first assumed it was heat damage so I moved the light up about an inch and set my fan to come on more often.

I am using 18 26W 6500k CFLs for my light. The temperature is steadily around 80 now but some of the other plants are starting to show similar results. I have now switched back to an 18/6 light cycle. I have only used neuts 1 time during the grow and am fairly confident I am not over watering. I only water about twice a week and use about 1 gallon distributed evenly to all the plants.

What could the problem be? Are my lights still too close?

Thanks for any advice.

Pics:
Plant A: Heavy yellowing around the edges looks burnt.
Plant B: Light Green/Yellow spotting.
Plant C: Light Green/Yellow spotting, yellowing around the edges.
Plant D: Light Green/Yellow spotting.
Plant E: Drooping, leaves curling up.

Click to expand...

Muffy said:

Looks like someone's got a case of the Miracle-Gros.

Click to expand...

timsatx1 said:

they look underwatered. look how your soil is pulling away from the sides of your pot. there are probably other issues going on to.

Click to expand...

blackmetal19 said:

That was my first thought but under the top layer of soil it seems pretty moist.

Click to expand...

keico said:

Ok first move that thermometer so they are laying on the flower pot itself. This will give you a better temp reading.

Second keep that fan on at all times.

Third what type of soil are you using.

Resist the urge to use fertilizer when the plants are young

Otherwise they look good. They will recover

Click to expand...

Green Cross said:

486w is a lot of heat

Get a bigger blower to exhaust the grow room

Here's a calculator

I'd go with a minimum of 250 CFM

Click to expand...

blackmetal19 said:

Thanks for the reply. I am using Pro-Mix potting soil. Each plant is in a 1.5 QT plastic planter; see the link below for the planter. Will I need to transplant these to bigger pots? Right now they are about 3 weeks old.

What about the yellow spotting, curling and burned looking edges? Anyone know what this could be? Heat Stress?

http://www.homedepot.com/h_d1/N-5yc1vZ1xkd/R-100205637/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Click to expand...

keico said:

I normally start off in the jiffy starter cubes, then go to a 1 quart pot.

Give them a couple weeks and when they are root bound transplant to a 3 gallon pot.

Using cfl they will not grow as fast, as if you were using a HID bulb

I started using cfls then switched to a 400 MH and then for flowering 400 watt HPS.

I wouldn't worry about the yellowing and tips that are burnt . They will recover believe me.

Don't move those cfls father away, as they have to be close in order to be effective.

The curling could be from heat but it is hard to tell since they are kinda young.

If you want you can have the fan blow directly on the cfl, that should help get some of the heat off of them

Click to expand...

blackmetal19 said:

How do I tell when they are root bound?

The only reason I chose CFLs over MH or HPS was because of the heat. There is no way I could run an HPS and get the heat out of that room.

Click to expand...

keico said:

You can look at the bottom the pot. If you see roots growing out and they are about 3 weeks old chances are they are root bound.

Also another way to tell root bound is the plants growth will be really slow.

Yes you can use a MH/HPS just get a cool tube and you will be ok

Check my signature you will see

Click to expand...

blackmetal19 said:

Anyone have anymore thoughts on what caused the yellowing spots on the leaves?

Click to expand...

blackmetal19 said:

So now I'm thinking it was neut burn. I went to my local nursery to buy more Pro-Mix and realized that I didn’t buy the plan Pro-Mix potting soil last time; I bought Pro-Mix Ultimate Container Mix Potting Soil. This stuff has time released fertilizer in it.

I bought the plain Pro-Mix potting soil and some 1.5 gallon pots (biggest they had besides the $40 ceramic ones, fuck that). I transplanted into the new pots 4 days ago and the next day the yellowing seemed to get worse. I read on here somewhere that it is better to cut off damaged leaves because the plant can then focus its energy on new growth instead of healing itself, any truth to this?

I did trim the damaged leaves off and today they seem to be doing a lot better. It looks like they are re-growing two new leaves for each one I cut off. Hopefully this works out now.

Click to expand...