Sick plants with stunned growth

[Warbat]

Hello all,

I have a number of plants that are showing some bad signs of nute burn, but I have flushed them with ph'ed water a number of times, and some plants have recovered, but these remain sick.
I am wondering if I might have a 2nd problem, or have caused a problem from the flushes.

I have had some Temp and RH problems, and possibly a PH problem to start off with.
These plants were seeded between Xmas and new years, and potted at the start of the year.

Strain - Mixed (Bag seeds, at least 3 different strains)
# of Plants - 15
Grow Type - Soil
Grow Stage - Seedling - Vegetative
Bucket Size - 9L (think thats 3 Gal).
Lights - 1 80x5watt MarsII panel (220watt output), 2 125 Watt CLF's with reflectors.
Nutrients - Seaweed cons
Medium - 66% potting mix (Horicons potting mix), 33% Per/Verc
PPM - I dont understand PPm of what in soil?
PH - 6.5
RH - I have to us aircon sometimes, so this changes from 45% to 80% depending on the Temp (Higher temp = higher RH).
Room Temperature: 24c-29c
Room Square Footage - 2x4 foot (currently, will flower in larger space).
Pests - None Known

Link to Gallery



Will try to clean up the photos when I have some more time.

Thank you for any help,
Warbat

 

[Dan Ultra]

Could you be more specific about the nutrients given? NPK values? It seems a little early to be feeding to me, how often are you watering? If you are using a pH pen, is it calibrated? 29c is a little warm, probably not the issue here, but keep that in mind.

 

[Warbat]

Thanks for the fast reply.
About the Neuts, I have been using Seaweed Liquid concentrate, and I have used alittle PowerFeed (14/1.2/9)(Dulited down to below 1/4, and only used once).
My PH has been used via a color change test, my pen is on its way.
Yeah, the temps are alittle high, but when its 35c outside, i'm doing my best

Could it still be Neut burn after 2 flushes a week apart?
Also, after 2 flushes, would I need to think about adding some more nuets to my next feed?

Thank you,

 

[Stealthboat]

That little plant doesn't need nutes yet. When there are 4 sets of leaves or more, then you can safely start feeding them. Not sure what the cause of the problem is though, everything seems fine from what you've told us. The flushes should have corrected any ph problems this early on. Temps of 29C aren't too bad if your RH is also high at this point, it's good for the veg stage to be warm and humid. What your ventilation like?

 

[Warbat]

I currently have the tent mostly open with a small desktop fan, but I also have an extractor fan that pulls heaps more then my little tent needs.
I some of my hotter days there has been some cases of 27-28c, and 40-50% RH, but that has been the extreme during some crazy hot days where the aircon could not keep up.

I guess it will be a case of wait and see, was just hoping to see more growth after 4 weeks .

 

[cannilingus]

gosh. just good, plain potting soil, can be too much on a young plants, without ferts. with young plants, i use soiless. and only give em some kagaroots, superthrive, and let em just be. when they are dry, try a 1/4 strenth, or less. but they need to grow up some.

 

[Teddy Edwards]

Hi Warbat. I think Stealth and canni have nailed it. Certainly do not feed, and that soil might be too hot (I learnt that the hard way). Flushing will not have done any harm.

How far from the LED are they? I've seen and read here that intense LEDs can be a bit much for the very small. I raised mine only under CFLs for the first few weeks before switching on the big boy.

 

[Warbat]

I thought it was the LED lights at one point and moved them up to be just over 2 foot from the top of m tallest plant, but have just lowered it 6" as I felt it was too high and the light intensity was not there (Love the panel, but it is the smallest MARS2).
The CLF's are about 1 foot away from the closest plants (and on each side of the LED with the reflectors bent to limit the blockage from the LED panel).