Orange spots and brown streaks

Hi guys,
I have 3 lowryders (2 weeks old), and they were doing great until I put them under a 400w HPS a few days ago.

One plant developed some orange spots on one fan leaf, so I decided to pot-up all 3 plants.

They seemed to be ok, but yesterday the third plant developed brown streaks on the leaves, which are now turning dry and brittle:




Today, the plant with orange spots has got worse:


They are planted in a mix of seedling compost, peat, and perlite. It's regular compost, NOT the slow-release stuff, and they have only been given water, no nutes.

Any ideas what could be causing these problems?
I've checked for thrips & mites, but there's no sign of any. Could it be nute deficiency? I thought the compost/peat mix would contain enough nutes for a few more weeks.

Please help if you can, thanks.

Happi - That kind of looks like a magnesium(mg) deficiency caused by hard water or a low ph. I had it big time very early on and I got some epsom salt and mixed in a spray bottle (make sure the epsom salt is disolved) and misted the leaves a few times a day and within a week, they were all better. I'm not saying I am positive that's what it is, but it does look like it.

Check out my grow journal and compare. The one plant on the first page ended up dying before I found what the problem was.

https://www.rollitup.org/grow-journals/30279-first-grow-m-s-feminised.html

Thanks for that, I read your journal and it looks very similar to what I have. I'm gonna go searching for epsom salts asap, thanks again!

you got it right on DM, after a couple days of epsom, go ahead and start a 1/8 strength solution of nutes, they are about ready.

Thanks guys,
I just got some epsom salts at a pharmacy, gonna dissolve in warm water and spray them now.

It's strange that my best plant shows no sign of this problem, since all 3 plants are using the same soil mix.

My plants are under 24/7 400w HPS, so I just took them out of the growbox, sprayed them, and then left them in bedroom light until they dried (15 minutes), then I put them back under the HPS. Is that ok? I can't think of any other way to do it without changing the light schedule.


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nah your good, your vegging now, so the light schedule isnt as important. Plants respond pretty slowly to light also, so even though the intensity of light changed, the plants probably didnt notice the difference. as soon as you start noticing the plant start to recover, go ahead and trim all the dying leaves off, then you plant will start focusing more on recovery, and new growth.

The Ganj Father said:

nah your good, your vegging now, so the light schedule isnt as important. Plants respond pretty slowly to light also, so even though the intensity of light changed, the plants probably didnt notice the difference. as soon as you start noticing the plant start to recover, go ahead and trim all the dying leaves off, then you plant will start focusing more on recovery, and new growth.

Click to expand...

Thanks a lot for the advice, much appreciated.

How often should I spray the leaves?

it just depends on what kind of mitecide you decide to get, always follow manufacurers instructions with that kind of stuff, even if its organic. Too much can still harm you plant.

Sorry, I meant the water + epsom salts (quarter teaspoon per 2 litres), not a chemical spray.

whoops, i should have followed that one, i would give them a mist every few hours, at least a couple times a day. you should see recovery quickly.

Cool, I'll give them a blast regularly.

Thanks again Ganj Father, you've been a great help .


I'll update this thread with my progress, for future reference.

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