leaf?

[m@rg]

im hoping its a calcium ? gonna have to ask the experts

SOIL:
What STRAIN are you growing? - bagseed
What was the establishing technique? --clone
What is the age of your plants? 10 wks
How Tall are the plants? about 20 inch from soil
What PHASE (seedling, vegetative or flower) are the plants in?- flower
What size pots are you using? - 1 plant in a 5 ltr pot
What Nutrient's are you using? - bio bizz bloom,topmax bloom stim,algamic
What method of pH test was administered?- pH pen
How often are you watering? - every 4 days ,feed every other watering
What size bulb are you using? - 600w hps
What is the distance to the canopy? 20 inch
What is your RH Factor? (Relative Humidity) - 60 %
What is the current Air Flow? (cfm etc.) - 125
Is the fan blowing directly at plants? - yes
Is the grow substrate constantly wet or moist? - moist
Is your water HARD or SOFT? hard
tap water adjusted ,no pests

only affecting 1 out of 6 strains,same soil,same feeding times
no signs of any burn on the tips ?

 

[HeadyPete]

Can you fill in the complete form please? What is the ph of your runoff?

Temps?

 

[m@rg]

soz
temps taken half way through light cycle
temps on floor -14.8 c
temp on canopy - 24.5 c
temps at night 12 - 14 c

run off ph - used ph 6.45 -run off at 6.77
had a feed yesterday of mollasses at 1 sp gallon
usuall feed 2ml ltr biobloom,2ml ltr bloom stim and 2ml ltr algmic

 

[HeadyPete]

Bingo! Your temps are way too low. Are the plants on the floor? That is a killer. Plants must be up off the floor or on styrofoam insulation or something.

Anyways, temps for MJ ideally are around 24 C in the day and about 18 min at night. Any colder and the plant can't take up nutes and starts doing funky things like you see on your leaf.

You could drop that ph a little, but it is still in range.

Let's get them warmer and hopefully they should recover quick. I don't think the damage will repair and you may lose a few more leaves before they are better.

 

[dontlockmeup]

Cold temps was my first guess too. I dealt with some of that a couple of months ago and my leaves had the same damage but it gets worse even for a few days after you get your temps up. leaves will turn yellow then brown and crispy. My clones grew a lot slower than normal cuz it took some time to rebound. Get your temps up and things will eventually get better.

 

[HeadyPete]

I think I just found that problem with my Mountain Jam plants vegging.

I thought I was crazy but they were just not growing very fast, stems are purple, leaves are light green and the lower leaves are yellowing and getting brown blotches, like you describe...

At first I thought I was underfeeding, but now I'm pretty sure it's low temps. My MJs are on the lower level of my veg chamber, right above the fresh air intake, and at night I think my temps are getting way down when the furnace kicks down low for the night.

Even though the thermometer was showing everything a-okay up top, the lower shelf is too cold.

I am putting them on a heat mat on a timer to try to correct this problem.

 

[m@rg]

ok thank you for your help heady pete and dontlockmeup
never thought it was my temps !
ill get right on to the temps straight away
all 3 fans i have are blowing at the plants 24hr
exhaust is also running 24hr
for a start ill turn the exhaust off at night cycle and switch the fans off

the only thing different from my last run (had no problems,cropped in jan) is a new inline fan for the exhaust.seems like its sucking too good.

im afraid i have no way of adding extra heat to the grow
also will try and insulate pots

thanks again


bagseed

 

[dontlockmeup]

If you turn your exhuast off keep an eye on your humidity. My humidity skyrockets at night. I have pretty much a sealed room that I run an a/c and dehumidifier in during the day because I use a co2 generator. I turn my exhuast fan on for night cycles to help keep the humidity down. Your fans circulating the air at night is fine. I run mine 24/7 to keep the air moving it helps prevent any molding. I used to shut all my fans off and learned from experience that powdery mildew loves those humid stale conditions. Just trying to help so you don't fix one issue and create others in the process.

peace

 

[HeadyPete]

Good call, dontlockmeup. I'd be real worried about molds and budrot if I shut down my exhaust. Perhaps a speed controller would do the job better. Leave the circ fans running 24/7, plants need good exchange of air to be healthy and circ fans do the job nicely. I have 3 running day and night. My exhaust runs day and night as well.

As for heat, get a plant heat mat or two large enough and put them on timers to come on at night. You can also get a rheostat control for them if they are too warm. These are perfect as they heat the root zone. If your root zone is warm enough the rest of the plant can take cooler conditions much better. Same with the opposite, if your roots are cool enough then the plant can survive higher heat above. This problem won't last as we come out of winter and it warms up.

Just for the record:

Powdery Mildew = cold and humid conditions

Molds and budrot = warm and humid conditions

 

[m@rg]

thank you both for your help
last night i turned all my fans off in night cycle,and now im reading ur post
lights have not yet come on,so i cant read the night temps/humidity yet .
but now im going to leave fans/exhaust on as usuall,and go and get a few heat mats

looking like its still only one strain thats not liking my temps

 

[HeadyPete]

Hardware stores may have "tomato greenhouse" kits on sale that include a large heat mat. just tell em you are getting your tomatoes started for the season if anyone asks...or tell them to mind their own fucking business :wink:

 

[dontlockmeup]

I hate when people at grow stores ask "what is that for?"
I was in a local shop the other day looking for blackstrap molases and got that ? I told em how it helped feed the micro's in your soil and I was hoping to find some before summer to use in my vegetable garden. Don't think they really bought that story. They seem sort of like stoners. Sucks living in a small town though. I ussually drive 1 1/2 hours into a city to do my garden shopping so I don't get a reputation around here.

pete is right heat mats should get you by for the next couple of months and then you shouldn't need it till next winter. Heat mats are good for taking cuttings though so you could still use em year round.

peace

 

[sirgrassalot]

I tell them it's great on toast.

 

[HeadyPete]

DLMU, get your molasses at the grocery store when you are buying your food and ask the checkout if she would like some of your gingerbread cookies when they are done. :wink:

My local grocery carries 3 different brands of blackstrap, including Grandmas or whatever the popular one is now.

I use BioBizz, which is derived from molasses, so I don't bother with the blackstrap.

I hear you, i drive 2+ hours to a big city with anonymous cash in hand to get my grow gear. I feel good everyday about it, it's so worth it.

 

[dontlockmeup]

pete- I have been getting my molases at the grocery store and have been using it for the last year or so. I was just in the local landscaping and gardening store to buy some new plants for my yard. I had noticed that they had maxicrop and some other organic nutes. I just thought they would have the blackstrap for gardening too.

It is well worth the drive to spend my cash anonymously at the hydro store in the city. I like the guys down at the hydro store too. I've had problems with a few co2 generators and I have been able to just go back to the store and they took care of it all.

M@RG- Give it a few days and let us know if the heat mat solved your problems.

peace

 

[m@rg]

priced up a 1200mm x 600mm heatmat - £120 gbp, and id need 2 of those
also saw 300mm x 300mm heat mats for about £5 ,and id need 22 of those
so i went and brought a fan heater with thermostat
leaving all fans running and the heater set on 19 - 20 c during dark
went to room just before lights came on and recorded some temps
soil surface is 19.5 c , and it seems air temp is at 21.5 c

so now day night air temps are 5-7 c difference instead of over 10+ c

 

[dontlockmeup]

cool man. that should get the job done.

 

[HeadyPete]

Wow that's pricey for the heat mats!

Now that your temps are up you will notice faster better growth and the plants can actually take more nutrients and will use up water faster. It will take a few days for recovery.

Nice solution, I wish you good luck for your garden.

Be sure to leave an update.

 

[m@rg]

thanks guys for ur help as u can see in this pic things were just turning funky in only a few days
hope this works, and has had minimal damage

ill post the finished result soon
u think the purple is temps or strain related

 

[MynameStitch]

u think the purple is temps or strain related


Yup!