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Multiple deficiencies; White Spots, Yellowing, Rusting, pH using ProMix Thread Tools Search this Thread
Old 03-06-2009, 12:21 PM #1

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Multiple deficiencies; White Spots, Yellowing, Rusting, pH using ProMix

How long has this problem been going on?
Ever since I got these babies. Always a problem going on, cant keep them all fully green!

What STRAIN are you growing?
Purple Kush

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

What is the age of your plants?
Multiple plants; all varies around 1-2 months

How long have they been in there mixture they are in now?(coco,soiless etc..)
ProMix BX, transferred from Rockwool (clones)

How tall are the plants?
Between 5-8 inches

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

What Nutrient's are you using?(If growing soiless)
Lucas Formula

How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
0 Grow -5 Micro -10 Bloom per 1 gal, Feed every third watering.

How often are you feeding? (If using soiless)
Watering when the soil is very dry, leaves droop or about to droop. (Once every two-three days w/ slight runoff)

How often are you giving nutrients? (If using soiless)
Feed every third watering, Never got to the third since I flush alot :(

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

Are you sure your calibration is correct on your equiptment?
Yes, three point calibration a few days ago

When was your last watering?

What is your water temps?
Around 60F

When was your last feeding change? (ie. grow-bloom-micro-additional)
About 3 weeks ago, changed from 1/3 str lucas every watering to full str every 3rd watering.

What size bulb are you using?
8 T5's

What is the distance to the canopy?
Around 6"
What is your RH Factor(Relative Humidity)?
What is the canopy temperature?
68-81F, 69F Average

Tell us about your ventilation, intake exhaust and when its running and not running ?
Open door, with one fan blowing in and one low setting, circulating over tops canopy

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? R/O Water at 5 PPM

Has plant been recently pruned, cloned off of or pinched
Yes, recently topped 11 days ago. But these problems were showing before that.

Have any pest chemicals been used? If so, What and When?
Are plant's infected with pest's No,

The rundown:
Im using ProMix BX with dolomite lime in 6in containers. They are about 5-8" tall. The strain is purple kush. I have multiple problems, alot which I cant identify even with the guides or searches. Third grow, but the first two times I was young and didnt really pay atttention to deficiencies. This time I want to do it right. I water with 5.9 R/O water at 1000> PPM (Lucas 1/3 str was around 300 I believe and full str is around 900. Runoff today was around 100-400 ppm @ 6.1-6.5 pH watering at 5.9 pH R/O.

This is one of the healthiest ones I have.

Problem 1: Twisted leaves

There are most twisty leaves if you look at the rest of the pics. This one was just a closeup. I heard the twisting can be because of the strain. PK/Purple Erkel, but Im thinking pH?

Problem 2: White Spots
Problem 3: Purple Tips

Both problems can be found on these pics. Purple tips is a P def I was told. Maybe just a pH lockout?

The Underside leaves of them. I have scouted for mites or bugs with eyes, 40x loupe and also using a plain white paper and gently shaking/brushing leaves to see if anything falls on paper, and found none. I check every day.

Problem 4: Leaves that grow out just fine and healthy, but as they age and get larger, they turn into yellow, rusted, drooping, older fan leaves.

They start like this.

Then end like this:

Problem 5: Rust on the leaves (pH problem or Mag?) I think it maybe a lockout as well since I have dolomite lime.

Problem 6: pH problem I believe. My runoff pH WAS 6.6 with 5.0 pH RO water, if I water w/ any higher pH then runoff will be 6.6-7.0, I think because of the dolomite lime, should I change my RO water pH to 5.9 and keep it at that regardless of the runoff? I cant seem to get 5.9 runoff :( because the more I water the higher (Alkaline) the pH goes.
For instance I first measured runoff of my media. It was around 6.5. I decided to lower it about .5 so I flushed it (3x size of container) with R/O water pHed at 5.7 (I was told soil would be .3 up or down of runoff)
The pH stayed the same when I checked runoff, so I lowered to 5.0 pH, and the pH went UP!!! So I stopped flushing, I think the dolomite in the soil is activating hard so its just balancing it out. SIGH

I checked runoff again today; I watered at r/o water 5.9 pH and it was at 6.1-6.6 pH, 100-400 ppm

I water them when they need them (when the soil dries out and the leaves sag just a tiny bit) which is about every 3 days. I had been flushing them alot since the white spots and other deficiencies occurred which started ever since I got them. They were in bad health when I picked them up.

I used to feed them 1/3 Lucas formula, but I seen some def's so flushed and I changed it to Full Lucas, the new growth seems green and healthy now, but the hurt leaves doesnt look like they are going to recover back to green.

During the time of pics I already changed to full Lucas formula (GH Flora : 5 micro, 10 bloom) every 3 waterings. New growth appears very healthy now, but the other leaves that were "hurting" doesnt look like they are recovering, is that normal? They are the bigger fan leaves. Should I just clip them?

I got abit of nute burn with the full lucas, so I flushed it again a couple days ago.

Here are some pics.

My questions would be:
1.what are the white spots/rust spots/twisting/yellowing bottom leaves caused by?

2.The plant was not fed anything when they were in a cup while as clones and thats why the older leaves are yellow (I believe) (They were new growth and turning yellow so I fed them after, but they never seemed to recover?) and always drooping (while green leaves dont) regardless of the media being wet or dry, but I have started a feeding program a month ago and the new growth is nice and healthy BUT the older leaves that were deficient are not recovering from the "yellow" rusted state, is this normal? and should I just clip them?

3. How to control the pH. I mean promix is a handful for me, first I had problems with it being to acidic, now when I transplanted I added dolomite lime to my mix, and the pH seems a tad high for soilless. Should I keep watering with very low pH water to get the "perfect runoff"? Even at 3.0 pH?

4. All the plants has healthy new growth but soon as they get older they start fading off to yellow and almost dead. Why is that?

Need help asap, thanks for dropping by.

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Old 03-06-2009, 04:21 PM #2
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one thing on flushing,alot of water can cuz the soil ph to fluxuate...just lik overwatering cuzes somtimes
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Old 03-07-2009, 06:10 PM #3

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just my guess. the soil looks dry, but it may have been overwatered at one point. and maybe some pests like mites, which sometimes show up in overwatered conditions. i bet you'll do fine. dont blow that fan too hard on them either.
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Old 03-07-2009, 06:34 PM #4
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ProMix BX is buffered against pH drift with Calcitic and Dolomitic Lime straight out of the bale. There is no need to put more lime in there IMHO ... it is Very Hard to overwater due to its superior drainage properties and ability to trap air And hold moisture. Your perlite looks a bit stained (possibly a salt build up) ... Are you pre wetting your medium before you feed? When you flush do you leave the plants foodless for any period of time? I'm in ProMix BX and I don't even own a pH meter. I roll with a 3 to 1 ProMix to Perlite medium and I Flush & Feed them every other day. whodair ... Mites don't thrive in a moist environment ... or live in the medium ... perhaps you meant gnats?

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Old 03-08-2009, 03:45 AM #5

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I had a problem with pH being too low, so I added dolomite lime (1 tbsp) per 2 gal and 1/4 perlite, I dont have drainage issues, the soil dries to the bone within 2 days (no flush) 3 days if I flush. I soak the promix and run alot of water through before transplant then add it in. I dont presoak before feeding. When I flush I check the ppm runoff and its usually 100< so I don't feed until the next watering.

I've had no issues with insects or pests to date. Some of the pics, the media seems dry because I didnt water them yet. I took these pics in a span of a couple days (before watering and after watering).
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Old 03-08-2009, 03:47 AM #6

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i use promix bs also. btw, i supplement with extra dolomite too cuz it helps me get through whole cycle.

anyways. It almost looks like a P def to me..but your ph looks fine, maybe salt buildup? id flush and then go from there
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Old 03-08-2009, 06:44 PM #7
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Here's the deal ... you need to get 2-3 times the amount of water that the medium will hold past those roots to sweep out the old salts Then feed them (if you know how to gauge how much your medium holds cool ... if not ... ask) ... I'm not talking just to fix this or every once in a while or every 2 weeks ... Every time you feed them or at the very least every Other time. And I would do that on Your established schedule (Yours are dry in 2 days and probably wilting in 3???) ... I don't ever flush them without feeding them (how would you like to have food available you can't eat because it's too salty then have it taken away and replaced with just water?? You'd be mad, hungry as fuck and looking a little sick) ... I don't put food on a dry medium (it wreaks havoc on the always forming root mass) ... and I don't add lime. My plants don't start to yellow like that until I tell them to by starving them in the end.

Old 03-08-2009, 07:00 PM #8

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When your using dolomite lime to buffer than its essential to let it sit mixxed up for at least a month if not longer, watered real good right after mixed. otherwise you get fluxuations like that due to the lime reacting to your soil. i would transplant in to a mix that you manually adjust the ph in or use the lime but let it ferment in your soil for a bit if you do this you should only have to check your ph, itll adjust itself and stay pretty close, which is usually perfect. thats why its called a buffer.
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Old 03-08-2009, 07:08 PM #9
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don't worry about the troubled leaves going back to green, focus on the new growth and what it is doing. You can't fix what already happened but if you try to fix it now you will only mess with the new growth.

Also doing too many flushes, not giving the plant at least a week to "bounce back" will also lag any progress. Sometimes letting them sit and fix themselves does work better than trying to add more to this, add less to that.

what type of lime are you using? prilled, crushed, powdered

also have you checked the roots? see if they are rootbound in that pot?

one pic looked like they were hungry for n, then another looked like a heat or ph issue but still wondering on how much room the roots have in there.

5-8 inches for a 1-2 month old plant is not much growth so maybe they want more room.

In the last month how many times have you flushed them? Have you let it dry out between flushing or do you keep doing it since you see more going wrong?
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Old 03-08-2009, 07:57 PM #10

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Ok, a few basics.

1) Flush the soil, and check the first water that runs out, and the last water that runs out, both for PH and EC/PPM. I have found out that flushing your soil before you plant anything is extremely important in avoiding problems later on. As well as ph-ing your soilless media or additions - grow rocks, perlite, rockwool - before using it in your mix or grow, by dunking it in low ph water (say 4.0 or 5.0) and letting it stand for a day and then readjusting the ph of the water as often as necessary. Also, perlite and grow rocks need to be flushed with water to get rid of the dust, which will block small root hairs and slow dow water and nutrient uptake.

2) R/O water

R/O water has all the calcium and magnesium taken out (as well as nasty stuff like chlorene and heavy metals). Therefore, try supplementing with CAL-MAG, or spray R/O water with just a little epsom salts added to bring the ec back up. Or spray with 6.5 ph water (for soil) with epsom salt added.

3) Overwatering

Also, do you have a drainage layer at the bottom of the pots that keep the drainage holes open? Because if they get filled with soil, they might as well not be there at all. Always use a layer of grow rocks or even perlite at the bottom of your pots.

4) Using a ph pen

You should put your calibration fluid, the ph pen, and the liquid you are going to measure in the same room and keep them there for at least half a day - so everything is the same temperature. You should put the ph pen in R/O water and later the liquid you are measuring, for at least half an hour before taking your measurement. That way, the pen can hydrate, and minimize the influence of temperature on your measurement. Measurements will become very quick and accurate.

5) Diagnosis

Purple stems on fan leaves (and stems) would suggest a magnesium deficiency, probably caused by the R/O water and plus t
he coco coir in your soil mix.

If you're dedicated, check out the use of biological controls - nematodes and predatory mites to control pests. Indoors, ladybugs and other winged insects can also be used. As a last resort, use pyrethrum based sprays to control a large outbreak (works well against adult fungus gnats, while their larvae can be killed with gnatrol).
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