Whats wrong with my girls?

[Kronikal_kiwi]

SOIL:

How long has this problem been going on? Ages, a few crops now.
What STRAIN are you growing? White Dutch, Hindu Kush, Afghani, White Widow, Hawaiian Skunk (all plants affected)
What was the establishing technique? (seed or clone?) Clones
What is the age of your plants? Numerous plants affected right from 3 week old clones through to harvested plants
How long have they been in the soil mixture they are in now? Again numerous crops/plants effected I have changed soils etc but same every time.
How Tall are the plants? Again, numerous plants from 6" clones through to 24" budded plants
What PHASE (seedling, vegetative or flower) are the plants in? Usually the plants are fine when they're small it's when they get to proper vegging under the hps lights (and away from the metal halide)
What Technique are you using? (SOG, SCROG etc) SOG
What size pots are you using? (Include how many subjects to pot) Lots of different plants from 2 litre pots through to 30 litre pots
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) Different mixes GRO (Peat, perlite, vermiculite, worm castings, dolomite) Max Yield (Coco fibre, perlite, worm castings, dolomite) and Daltons pot power (Bark, Slow release fert's, and a few other bits and pieces)
What Nutrient's are you using? I've changed a few times thinking it may be nutrient based. A local fert called Mr Grow and Mr Bloom, an organic one called Guano Super bloom and Super Grow made out of bat guano, and I've tried canna terra nute's
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* Canna I tried useing the reccomended dose of 5 mils per litre but then I upped them a bit cause I thought they werfe a bit low. I was running 5 mils of Terra Grow 2.5 mils of Cannazyme and 0.5 to 1 mil of Rhizotonic. I upped it to 7 mils of Canna grow.
How often are you feeding? All over the place I tried once every watering, once every second, once every third nothing fixed it.
If flowering, when did you switch over to using Bloom nutrients? I slowly introduced them from the beggining of flower and weened down the veg nutes
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) Um don't know sorry.
What is the TDS/EC/PPM of your nutrients used? I tried running around an EC of 10 during early veg up to 23during mid bloom.
What is the pH of the "RUN-OFF"? Don't know sorry
What method of pH test was administered? Using Strips? pH pen? Didn't
How often are you watering? Um when they get dry probly around once a week
When was your last feeding and how often are you feeding? I fed my vegging girly around 5 days ago.
What size bulb are you using? I use a 400 Halide for early veg and I dont see the problem but then they go under a 400 or 600 HPS and I quickly see this damage.
What is the distance to the canopy? I've tried everything from a foot to 3 and a half feet still no difference with the burning
What is your RH Factor? (Relative Humidity) Very low around 25%
What is the canopy temperature? Um quite cold it gets up to around 28 degress celcius 83 degrees farenheit.
What is the Day/Night Temp? (Include fluctuation range) It gets right down to 16 degrees celcius during lights off 61 degrees farenheit and it gets up to 28 degrees celcius or 83 degrees farenheit durinjg lights on.
What is the current Air Flow? (cfm etc.) quite a bit 300 cubic metres an hour controlled by a thermostat
Tell us about your ventilation, intake exhaust and when its running and not running ? I have a 150 mm centrifugal fan sucking air out of my main area with the hps lights. there is a cool tube which is sucked via another 150 mm centifugal fan
Is the fan blowing directly at plants? I have an oscilating desk fan that runs on low breeze at the plants
Is the grow substrate constantly wet or moist? um I try not to let it be but it does tend to stay quite damp for a while cause the weather is so cold around here.
Is your water HARD or SOFT? Soft
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? Nilnat which I think is similar to Gnatrol
Are plant's infected with pest's? Yes fungus gnats

Hey guys I've had this problem for ages and it's really starting to upset me ALOT. I simply cant afford this crap. I have changed soil, fertilisers, temperatures, humidity over this and nothing prevents it happening. First the leaves yellow from the bottom and dry to a crisp until the whole plant is fucked. It really cuts into my yiels so much so that I threw my last lot away (25 plants under a 600 in a 4ft by 4ft area) cause they were so burnt and at 6 weeks they had f*ck all bud on them. I'm really getting miserable over this shit. It affects multiple stains and nothing seems immune. They start off healthy and when they go under the hps's they start almost immediately it seems to be getting more and more rapid with each batch of clones. I have had fungus gnats for ages and suspect possibly the roots are getting so stuffed that the plants start to die above the soil? They dont have signs of pythium wilt and never have. I dont believe it's a nutrient defficiency as I;ve tried numerous different ferts with different soils at different rates and it still doesnt change anything. Anyway heres some pics

 

[Hydrosun]

Go soil-less and use RO water, then you know exactly what is in with your ladies. It is really easy, and a lot easier to keep the plants happy than soil.

Peace

 

[Hazy Lady]

If this has happened over a few crops, with diff' soils, diff nutes i am sorry to say that it follows that you are doing something wrong, I don't grow in soil these days but that looks to me like you have simply applied feeds that are too strong and too often to the point you have salted up each grow and ended up with this, i feel sure if you tested the run off it would be massively salty, 5.0 or less and your girls can't take up anything, most soil/compost shop bought has all the nutrients plants need for around 6 wee'ks so you should not be feeding until your plants start to lighten and look in need of some food

 

[Hazy Lady]

Ok, i read your diagnosis chart and must point out a couple of things that are VITAL for you to ever produce some nice flowers, with nutrients it essential to follow the makers instructions, not so much in the amounts of each part, you can adjust to suit each strain but in the order in which you mix, this must never change or you will have problems, when mixed the wrong way they can produce flakes of material that looks like calcium build-up, your plants can not use this and of course they will suffer, also you do not use any PH control, again VITAL to avoid problems and again to rectify any as they arrive, you say you "can't afford this ***" well you can't afford not to in my opinion, right now you need to fix the issue you have, flush and flush the soil until you feel it is almost clean water running out, then allow to recover for a few day's, if you have been lucky new growth will appear and you can start very gently feeding, mixed the right order and not a lot, hope it goes ok for you.

 

[hempluvr]

Do you flush your plants at all,if so how much? You flushing enough? I grow in soil in 3 gallon pots. I flush with at least 9-10 gallons of water per pot 2x per month. Plants love it and it prevents toxic salt buildup. Like Hazy Lady said feeding those plants to much food WILL cause a serious problem. Ph drops below 5 and you have some serious problems. Some strains even like a higher PH in soil and 5 would be to low. When the PH drops that low you get what is called a lockout. PH being low will lockout certain nutrients and cause the plant to go into shock or possible die if the problem is to bad. Flowering becomes retarded and yield is lost. Slow your feedings down,use RO or distilled water. Your plants being under and hps is not the problem. The problem lies in your medium. I veg under a 400 watt mh and flower under a 600 watt hps and have had no problems except for ph,which I have corrected now. Don`t assume what is going on in your medium,know what is going on.

 

[ReeferRon]

One thing that needs to be corrected is the 22 degree change from dark to light. From 61f to 83f is to much of a change and can cause all kinds of problems. I dont know if it has anything to do with the yellowing and burnt appearance of the plants but its not good and will effect yield. Lights on should be 78f at the canopy and 72-68f for dark. That huge fluctuation causes stress. Also it looks like your soil is awfully hot and I would be willing to bet you got nute burn and lock out from over feeding and not adjusting soil ph to the correct levels.

 

[The Southpaw]

If this has happened over a few crops, with diff' soils, diff nutes i am sorry to say that it follows that you are doing something wrong, I don't grow in soil these days but that looks to me like you have simply applied feeds that are too strong and too often to the point you have salted up each grow and ended up with this, i feel sure if you tested the run off it would be massively salty, 5.0 or less and your girls can't take up anything, most soil/compost shop bought has all the nutrients plants need for around 6 wee'ks so you should not be feeding until your plants start to lighten and look in need of some food

I am thinking that the Hazy Lady is spot on..
Peace!!

 

[Hazy Lady]

Thanks TS,
I must say Hempluvr summed it up very well with one short line :- "Don`t assume what is going on in your medium, know what is going on."

 

[Kronikal_kiwi]

Hey everyone. Thank's for the replies! Awesom to see so many people willing to help me! Well, I'm gonna give what you all say a try. I didnt think it would be over feeding as I know what nute burn looks like and I cant see it, however you are all right I'd say that there is nutrient salt build up in the soil. I shal start flushing. I used to Water Feed, Water Feed but I wouldnt call it flushing as I didnt give huge amount of water and flush out the soil fully. I shall start up a thread tonight on some VERY healthy clones I have under my MH right now so you can all follow and hopefully flushing will make a huge difference! I cant afford a PH meter right now however I know this soild tends to give pretty mint results and I'm sure lotsa soil guys dont use PH, do they? Anyway I'll post a link to the new grow in a litle while.
Cheers again guys!

 

[Kronikal_kiwi]

Hey people. Well this problem seems to have reared its ugly head again. I definately flushed guys. Fed very low amounts (500-700ppm). I've let the girls dry thoroughly between waterings. It's a diferent batch of clones this time, Afghani. Here's a link to the thread http://www.icmag.com/ic/showthread.php?t=130709.
You can see how I got them healthy and green by raising my night temps but now the problem has returned! I'm worried about switching them as this problem almost always results in complete failure with budding the leaves all start to yellow significantly befor the plants look almost entirely light yell nearly dead by week 4-6.
Heres some pics


I fed them epsom salts last night. Although I doubt it is a Magnesium deficiency as the veins are yellowing aswell as the rest of the new growth rather than staying green. Anyway thanks for taking the time to have a look.