Yellowing slow new growth, purple stems, brown spots - Pics

[FarmerGreen]

I'm growing some bagseed under a 250w in a mix of worm castings and very plain potting mix.

When I first transplanted them into the worm castings they loved it, took off real fast, but in the last 2 weeks they have slowed right down and begun to yellow with some leaves dying off completely. There seems to be unusual discolouring to quite a few leaves, both at the tips and throughout the leaf.

The bulk of the vegging so far has been with a HPS bulb, but a week or so ago I switched to a CMH bulb, but that was after it already looked sick.

Could it simply be from having the bulb too close?

I'm thinking I might just repot them into some regular potting mix and leave out any worm castings, but if there are any suggestions on how to fix it I'd love to give it a go.

I was about to flip to 12/12, but I don't want to until they are super healthy.

This plant is the worst of my 3, but the other 2 are also starting to show signs of discolouring.

 

[FarmerGreen]

So I noticed everyone was filling out these forms on this thread, I thought I'd do the same in the hope of getting some help...

How long has this problem been going on?
2-3 weeks

What STRAIN are you growing?
Bagseed

What was the establishing technique? (seed or clone?)
Seed

What is the age of your plants?
6-8 weeks

How long have they been in the soil mixture they are in now?
3-4 weeks

How Tall are the plants?
Currently scrogged, so hard to tell, reaching maybe 18 inches on the screen

What PHASE (seedling, vegetative or flower) are the plants in?
Veg

What Technique are you using? (SOG, SCROG etc)
Scrog
What size pots are you using? (Include how many subjects to pot)
12 inch high pots, 1 plant per pot.

What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?)
About 1 third soil, 2 thirds worm castings

What Nutrient's are you using?
Nothing except one dose of half strength earth juice.
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
As above

How often are you feeding?
only once

If flowering, when did you switch over to using Bloom nutrients?

What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)

What is the TDS/EC/PPM of your nutrients used?

What is the pH of the "RUN-OFF"?
unmeasured

What method of pH test was administered? Using Strips? pH pen?

How often are you watering?
once every 2 days recently, but once every day when they were growing fast, seemed to be using it all

When was your last feeding and how often are you feeding?
about 6 days ago

What size bulb are you using?
250w
What is the distance to the canopy?about 10 inches away, but earlier it was only 5 inches away
What is your RH Factor? (Relative Humidity)

What is the canopy temperature?
77F
What is the Day/Night Temp? (Include fluctuation range)
77/59
What is the current Air Flow?
I think about 100 cfm(cfm etc.)
Tell us about your ventilation, intake exhaust and when its running and not running ?
Main fan (exhaust) is only running when lights are on, very light intake fan runs all the time as does a circulation fan.

Is the fan blowing directly at plants?
No

Is the grow substrate constantly wet or moist?
No

Is your water HARD or SOFT?
Hard I think

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
Tap

Are you using water from a water softener?
No

Has plant been recently pruned, cloned or pinched?
No

Have any pest chemicals been used? If so what and when?
No

Are plant's infected with pest's?
No

 

[s13sr20det]

What is the pH of the "RUN-OFF"?
unmeasured

sorry i cannot help with your problem, but knowing the ph is crucial!! you can have all the nutes in the world, but if the plant cannot take them up they are useless.

you can get an inexpensive strip/drop kit at petco and petsmart in the aquarium section for about 3 to 5 dollars

peace

 

[FarmerGreen]

Would dolomite lime in the soil help? I forgot to mention I put that in

I've got one of those cheap dropper mix tests, but how do you tell the colour if the water is brownish to start with?

 

[FarmerGreen]

Both the run off and the water straight from the tap seem to be sitting around the 7.2-7.4 mark which I guess is a bit high. I'll try bringing it down to the 6.5 mark and see if that makes much of a difference over the course of the week

 

[Dr Dog]

did i read that right and you have 2/3 worm castings in your mix?

 

[FarmerGreen]

did i read that right and you have 2/3 worm castings in your mix?

yeah round about, too much?

 

[Dr Dog]

ermm yeah by about 2/3rds

That is an additive, not a medium. Super high is nutes that be... I use it at a rate of like 5tbs per gallon of soil/promix

 

[FarmerGreen]

Ok. So I just repotted the plant that was doing the worst, replacing as much of the wormy soil with ordinary soil, not that easy cos it already had a shit load of roots throughout. And I dropped the ph of the water in the resovoir to about 6.5ish.
I guess I'm just kind of treating this plant as a bit of an experiment now, I"ll let you all know how it goes.
The other two plants in the room are doing a lot better than this one, I don't know why they would be so different, bagseed I guess.