black spot, shadow

[begbie5]

Hi to everybody
My name is Dan i have a problem with my 3 week old plants.
I grow them under 600hps, 12inch from a lamp.
I had a small deficiency of N few days ago, but that problem was sorted.
Ph of soil is 7, water between 6-7 (do my best to reach 6.5).

there was a problem with humidity so started spraying leaves with water for a night. I did it every night and started 3 days ago. I sprayed the well with a water.

Today morning one plant got some black shadows/spots on bottom leaves. The other three are okay. Problem is on Ice cool, i had a loon with magnifying glass, but cant see anything, its only 10 times. Will have microscope x30 in the end of the week, but for now dont know what to do.

2 days ago i moved plants to bigger pots and mixed soil with worm casting.
I have no idea what has happened.

If u have some ideas please help me.
Thank you

begbie5 Reviewed by begbie5 on 07-05-2010. black spot, shadow Hi to everybody My name is Dan i have a problem with my 3 week old plants. I grow them under 600hps, 12inch from a lamp. I had a small deficiency of N few days ago, but that problem was sorted. Ph of soil is 7, water between 6-7 (do my best to reach 6.5). there was a problem with humidity so started spraying leaves with water for a night. I did it every night and started 3 days ago. I sprayed the well with a water. Today morning one plant got some black shadows/spots on bottom leaves. Rating: 5

[Rusty Trichome]

For starters, your growroom looks like a Radar Range. I'd ditch the foil on the floor. Especially if the 600w is 12" from the plants. (will act like a Radar Range, too) What are your temperatures?

What were you considering 'low' humidity? High humidity coupled with high heat promotes mold. Moisture can and will get trapped between leaves, and trapped or standing water (on or inbetween the leaves) is a bad thing.

How much worm castings did you add to the mix? Too much, and the soil becomes more muddy than usable. (suffocates the roots)

You can still OD a plant using organics. Although castings are organic and slowly release nitrogen...the more worm castings you add, more nitrogen is being released.

If more help is needed, fill-out the CanCom troubleshooting form. :thumbsup:

[begbie5]

what is that mean radar range?
temp is 25 on tops, humidity is 45, before was 30
i mixed 1/4 worm castings and 1/4 perlite

should i go lower with lamp, if temp is not higher than 25 on top of plants?
thank u

[begbie5]

What is your experience level? (first timer, novice, experienced...)

Your Equipment:
.1) Type and wattage of lights - 600 HPS
.2) Distance from tops? 12inch
.3) Reflector type? (cool tube set-up)
.4) Is there a consistent fresh air supply? yes
.5) Do you have an exhaust fan and a circulation fan? yes

Your medium:
.7) Specific brand and type of soil: potting compost ph7, 1/4 perlite, 1/4 worm castings
.8) Size of container. 7inch
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings? no

Your nutrients and water:
10) Source of water? tap, What's it's ph before adjusting? ph9
11) Method of checking water ph. (GHE concentrate test indicator)
12) Method of adjusting water ph. (PH down)
13) Specific brand and N-P-K ratio for each bottle. plagron alga-grow 4ml/1L
14) How often are you watering between feedings, and how much per watering? every 2 days, 400ml
15) Any additives or tea's? (not yet)
16) Are your ph levels stable, or do they fluctuate? stable
17) What is your ingoing water's ph? ...your runoff ph?
18) Do you foliar feed? If so, with what, how often, and at what time do you spray? no

Your growroom:
19) Indoor
20) 1,2x1,2x2
21) What are the temps and humidity levels while lights are on? ...With lights off? 45/25 lights on 70/19,2 ligts off
22) Have you seen signs of insects in the growroom? no

Your strain:
23) What strain are you growing? Indica, Sativa, Indica / Sativa, Mostly sativa
24) From seeds or clones? seeds
25) Is this an autoflower strain? no

[Rusty Trichome]

what is that mean radar range?

Amana Radar Range. A microwave oven with a stainless steel interior.

temp is 25 on tops, humidity is 45, before was 30

25 to 30 c. (77 - 86 f.) is fine. Personally, I prefer slightly higher temps to begin with. (I live in the desert...check the Dealing with Heat Issues link in my signature) I never spray my ladies. If they aren't getting the moisture from root uptake, they don't get it. (they adjust just fine if allowed to do so)

i mixed 1/4 worm castings and 1/4 perlite

What did you mix the 25% perlite and the 25% castings into? If the potting mix you use already has castings or another nitrogen source, it might well be overkill. But my main concern would be the results from too much of the worm castings making your medium too muddy though. Retains water, locks-out air and gasses necessary for roots, and root rot will develop if not letting soil dry between waterings.

should i go lower with lamp, if temp is not higher than 25 on top of plants?
thank u

Tiz up to you and your plants. Is your 600w in a cool tube?
Are you in the middle of summer, or the middle of winter?

[begbie5]

Tiz up to you and your plants. Is your 600w in a cool tube?
Are you in the middle of summer, or the middle of winter?

in the middle of summer, but weather is like spring, 600hps is in the coll tube,
i lowered lamp to 10 inch for a test and temp is 29,2.

i found somewhere to mix 1/4 perlite and castings, change castings to 1\8?
thank u

[Rusty Trichome]

Your Equipment:
.1) Type and wattage of lights - 600 HPS
.2) Distance from tops? 12inch
.3) Reflector type? (cool tube set-up)

Figured it must be a cool tube. What's your current lighting schedule?

Your nutrients and water:
10) Source of water? tap, What's it's ph before adjusting? ph9
11) Method of checking water ph. (GHE concentrate test indicator)
12) Method of adjusting water ph. (PH down)

Ouch. Mine's 8.0 ph out of the tap, I use phDown too. What ph are you adjusting the water to?

13) Specific brand and N-P-K ratio for each bottle. plagron alga-grow 4ml/1L
14) How often are you watering between feedings, and how much per watering? every 2 days, 400ml

Is this the stuff...?: Plagron Alga-Grow - £6.95 : Gavsgrow, Organic and Hydroponic Garden Supplies
Usage: Dilute 1-2 ml with 1 litre of water. Water the plants with this dilution once a week.
N:P:K - 4.0:6.0:8.0 - A flowering formula. Sort of. Shitloads of potassium, possibly screwing with your ph.

15) Any additives or tea's? (not yet)

A little info about teas: Compost tea myths...

[begbie5]

What's your current lighting schedule?

16hours /24h

What ph are you adjusting the water to?

6.5 but using the concentrate indicator, so might be between 6-7

s this the stuff...?: Plagron Alga-Grow - £6.95 : Gavsgrow, Organic and Hydroponic Garden Supplies
Usage: Dilute 1-2 ml with 1 litre of water. Water the plants with this dilution once a week.
N:P:K - 4.0:6.0:8.0 - A flowering formula. Sort of. Shitloads of potassium, possibly screwing with your ph.

this is it. on the sticker is written use it every time u water plants, if deficiency use 4ml per 1 liter

i had it, bottom leaves were getting yellow color, so were adding 4ml and helped.

A little info about teas: Compost tea myths...

i order guano bat and gonna follow the link

thanks

[begbie5]

i dropped a lamp 2 inches down, so now i have nearly 30C. nearly but not over.

[bigtopsfinn]

You're in good hands here but take it easy with that light, no need to add any extra stress until the problem is resolved. Personally I'd transplant the problem plant into a slightly larger container with plenty of perlite and regular soil to make sure the roots aren't suffocating. Wait and see what Rusty (or other more experienced growers) says about this before doing it.

Any way of measuring the run-off ph? If using the color strips or drops, tinted run-off will skew the results. Need a digital ph pen for that. Hope you get it figured out :jointsmile: