organic garden, yellowed tips and tops,possible over fert??

Greetings fellow gardeners...

I was hoping to seek your collective advise re the problem in my grow.... (see pics)

Firstly some background.

The 5 plants are in veg (week 3 approx) the strains are unknown (possible 2 plants indica dominant, 1 sativa/indica equalish mix, 2 sativa dominant) also the plants had been allowed to go into flower from being a couple of weeks old then were given to me and have been in veg 3 weeks or so. The plants had begun to develop pistles, hairs and rudimentary buds (the were in flower maybe a couple of weeks) although they were fairly spindly (maybe 8-9") when they were put back into veg there was some strange leaf growth (to be expected whilst reverting) but after a week or so looked reasonably healthy. At this point they were in small pots (5") filled with potting soil being fed some very diluted nutes @ 4ml/gal (unsure of brand as was given in a lucozade bottle from the same guy who gave me the plants)

The plants are under 600w hps dual grolux bulb, in a greenroom grow tent (roughly 2m high, 1.5m wide and 2m deep) there is a good cfm rated extraction fan mounted above the light with additional fan in the tent for circulation, temp steady at 80 deg F.

now to the issue....

4 days ago i transplanted each into a larger maybe 3 gal pot. this is the mix i have used based upon some experience and research/talking with other growers..

I used a litre jug as a single unit of measurement...

3 parts peat free compost (fairly dark and barky)
2 parts potting soil (for seedlings and cuttings)
2parts worm castings
2parts pearlite
1part vermiculite
4 tbsp bat guano (powdered)
3 tbsp garden lime (small balls, not powdered)
3 heaped tbsp seaweed (dried medium chopped, similar to tea grains sized)
2 tsp epsom salt

The above went into a single pot plus the plant obviously (should give you an idea of the size pot they are now in)

They were given only water the first 2 days and looked to be responding well, new growth looking healthy, good dark (but not too dark) green etc. however on day 3 i noticed the tips of some of the new growth had turned yellow and there seemed to be a bit of clawing) they were then given water with 1tbsp molasses mixed in a gal (each got about a litre or so as normal) the following evening (ie tonight) ive come in to see the clawing the same (at least it doesnt look to have gotten worse) but a quite serious yellowing of the new growth and some of the centres of the top leaves......

This happened on nearly all the plants except the seemingly indica dominant plants who look good (pic 1)

However on the sativa mix and the sativa (thinner longer leaves etc) the yellowing is quite pronounced...

Having looked into what may be causing the problem im still a bit confused and would love some imput...


The clawing indicates burning... this shouldnt be from the worm castings, poting soil or the peat free compost... perhaps it is lock out (theres loads of N available) due to the potent bat guano...it reccomended the dose given...possibly also as there is barely any lime in the mix...appears i have under limed (apparently a common issue for newbie organic growers such as myself... i have a fairly strong solution ready to be used although am hessitant of doing too much at once for fear of burning them.... oh and my ph pen has broken so am uncertain of the levels hence the idea to add more lime as a buffer


pic 1 indica dominant pic, seemingly happy
pic 2 sativa/indica mix....less happy
pic 3 sativa...very unhappy...


Any help would be appreciated (and thanks for reading this beast!)

peace

krumpit

Clawing as well as yellowing leaves with green veins points to MG deficiency, very common. I personally use Cal-mag mixed with my RO water to supplement and rarely have issues, but just up the dose in rare cases. Some people use epsom salts, its cheaper though I don't personally know the proportions or application methods. Cal-mg from GH at least acts as a PH down for me, so puts my feedings into perfect range. Never found a need to use anything else.

I am going to agree with the lockout thought. If I were in that situation, I would stop feeding anything extra at all. It seems there is more than enough nutes in your mix for plants that old. With all the shock they have been through and with bagseed especially, I would consider flushing and just letting them do their thing. Remember cannabis wants to grow, no need to over-complicate.

maybe nutrient lock up, if all the bacteria from the organics, guano, worm castings is consuming everything. kind of sounds like seedling potting soil and all the compost might retain too much moisture . if they keep getting worse you might just try organic potting soil like ocean forest. the same thing might happen though if they were just too far from the light.

warning Will Robinson!! peat-free......kinda barky? a pine product, perhaps? if so.......re-pot. that shit is acidic poison.

Thanks for the input guys...

ok so the peat free compost says it has composted bark and green waste, it also has added nutrients! arrg....didnt see that previously....... could account for clawing perhaps...I also do think theres a lockout issue...wish i had a ph pen here (will invest in a new one tomorrow)

@scroglodyte.....So a repot is needed you think... it doesnt specify if its pine but i get your drift...barky = no no, may get a pen and test to see what it reads before stressing them again by repotting, besides i have no alternative avail atm, however i may go for some FF or similar if i have to repot...

@ hydrosoil......they seem to have adequate drainage (run off at about correct rate) and they bout 9"-10" from the light so shouldnt be an issue.....

@ oilas..yeah water all the way until the issue is correctly identified...

@roidrage...ok but mg deff this early seems strange..i do have epsom salts here but am not sure about adding more variables into the mix untill have at lease checked ph......


so I take it more lime at this point is also a bad idea?

cheers again

good luck, m8!

cheers scroglodyte....

any further thoughts or thoughts on the lime addition or possible mg deff (as roidrage suggests) anyone?

re-pot into the right mix, and i bet it all works itself out, if not, sure, they look mag hungry. but give them time to show you what they're gonna do.

cool thanks.. yeah sage advise i think.....

will see what happens in next 12-24 hrs and act accordingly... repot seems sensible and will keep an eye on the Mg deff symptoms.....

Ill let you all know what happens in the next day or so... will include pics...

Many thanks....

Peace

ok so further update as to the situation...

ph of the run off (was careful not to contaminate sample) is very alkali (8 or 9 maybe) this may account for the Mg def symtoms as is locked out at this range as well as some of the other symptoms (can anyone confirm this from experience?)...... (i couldnt get a proper ph pen so am relying on liquid testing with a solution, not great i know but at least is giving me a reading)

The peat free compost, although barky and dark, testing the compost itself and water from the compost, shows as being also very alkali (strange as was expecting the opposite)....

my question is, will adding more garden lime suspended in water do the job of buffering ph down? or does it only work the other way ie if it gets too acidic it kicks in...

or would you recomend lowering of ph by adding blood meal for example (although already a fair bit of N in from worm castings)...... or by ph down additive eg vinegar (just as example...wouldnt like to use it but any other suggestions are welcome)

cheers to all,

peace

Get some ph up & down solutions, it's the easiest way to adjust your water PH. If your PH really is 8 or 9, that is your problem. It definitely is showing MG def, but probably because of lockout. You should be PH adjusting all water before watering your plants.
And NO on the lime! You need your PH down, not up. Lime is a base, you need an acid to lower. Some use lemon juice, but I still suggest getting some PH down (and PH up for when you need it). I switched from the liquid PH solutions and went to the powdered form, I love it and will never go back to the liquids. In case you're unfamiliar with the products, this is what I am talking about. And this is the powder form.
I wish you luck!
GS

yeah i agree Godslave,

i havent added any lime, i have used a very mild acidic vinegar solution and will continue to monitor over the next few days, it most likely is a lockout issue so hopefully this will remedy the alkalinity issue in next 72hrs or so......

will post some pics later...

cheers all

peace