Yellow crispy fan leaves on 4 different strains.Deficiency or hard water?

[stefanosstef]

Hello people.It's been about 10 days I have this problem and it seems it's getting worst gradually.I'm growing 4 different strains:Masterkush, Super Silver Haze, Ice Cream and Blue Cheese.


Here are some pictures:
Attachment 279005
Attachment 279006

And the most affected plant, masterkush:
Attachment 279007

I've switched to 12/12 5 days ago.I'm using a 400 watt HPS and it's 45cm away from tops.Not overwatering or underwatering, temps 27-29 C lights on and 20-21 C lights off.I've fed them twice with biogrow, 1/3-1/2 of minimum suggested dosage and ten days later I added biobloom, 1/2 of minimum suggested dosage.It's been a week since the last.I'm using tap water which I let it sit for 4-5 days prior to watering.I suspect that it's the water though because it's very hard.

I've been searching pretty hard and the symptoms look like potassium or phosphorus deficiency or light burn.Light burn seems unlikely because of the light distance.I can't check the ph but since I've fed them very lightly I don't think it's off.So what's your opinions?

stefanosstef Reviewed by stefanosstef on 10-05-2011. Yellow crispy fan leaves on 4 different strains.Deficiency or hard water? Hello people.It's been about 10 days I have this problem and it seems it's getting worst gradually.I'm growing 4 different strains:Masterkush, Super Silver Haze, Ice Cream and Blue Cheese. Here are some pictures: 279005 279006 And the most affected plant, masterkush: 279007 Rating: 5

[Salvein211]

Your light distance is ok, it could even be closer imo (12inches). Ive used 400w before, so I think 12in is a good distance depending on size of grow. I know nothing on those nutrients you use and their dosage so I cannot comment, but pH is a huge deal. When you add nutrients to water, you are lowering the pH of the total solution. I have a 7.3 pH coming out of my tap, and when I add nutes to a batch of water to apply to my plants, it isnt uncommon to see low 5.0 pH levels, which is WAY WAY to acidic. Also, for soil chemistry reasons, if you have too high or too low pH, which I think you have too low pH, nutrient lockout happens. It surely does look like you have nutrient deficiencies, but I cannot tell you which because I dont know.. But you might be changing your soils pH as you feed your plant over time, which is how lockout of nutrients happens. So if you continue to add nutes, you build up acid levels in the soil and will kill the plant. Also, a really good way of telling this is to check the pH 'runoff' . The water that drains out of your soil. This will tell you what your soil pH is approx... For soil it should be like 6.6-7.0 imo... I know you dont have a way to check pH levels, but I highly suggest you get pH test strips or even better a digital meter that checks it.

[stefanosstef]

Your light distance is ok, it could even be closer imo (12inches). Ive used 400w before, so I think 12in is a good distance depending on size of grow. I know nothing on those nutrients you use and their dosage so I cannot comment, but pH is a huge deal. When you add nutrients to water, you are lowering the pH of the total solution. I have a 7.3 pH coming out of my tap, and when I add nutes to a batch of water to apply to my plants, it isnt uncommon to see low 5.0 pH levels, which is WAY WAY to acidic. Also, for soil chemistry reasons, if you have too high or too low pH, which I think you have too low pH, nutrient lockout happens. It surely does look like you have nutrient deficiencies, but I cannot tell you which because I dont know.. But you might be changing your soils pH as you feed your plant over time, which is how lockout of nutrients happens. So if you continue to add nutes, you build up acid levels in the soil and will kill the plant. Also, a really good way of telling this is to check the pH 'runoff' . The water that drains out of your soil. This will tell you what your soil pH is approx... For soil it should be like 6.6-7.0 imo... I know you dont have a way to check pH levels, but I highly suggest you get pH test strips or even better a digital meter that checks it.

I can't check the ph for now but I don't think it's the issue here because I've only fed them twice and very lightly.It looks like deficiencies to me so I am thinking I should feed the 3 of them tomorrow and flush the masterkush.Do I have the OK from you?

[stefanosstef]

3 years ago I tested the ph of the tap water and it was 7.5-8, that's why I bought a ph-down solution.I just remembered that.So today I gave them nutes + ph-down hoping to fix the hypothetical ph issue.I won't be able to test the run-off ph until Monday.

[WashougalWonder]

Could be as simple as needing repotting. Get a troubleshooting form filled out. I don't think you have a serious problem....yet.....lets figure it out before you throw everything at it.

[Rusty Trichome]

If you can't afford a $7.00 freswater aquarium ph test kit, you can google your local water quality report, which should have pertinant information about your local tapwater.
But Like Washougal said...please copy-n-paste the troubleshooting form here, and fill it in as best you can. (no guesswork...if you don't know, just say so)

[stefanosstef]

Could be as simple as needing repotting. Get a troubleshooting form filled out. I don't think you have a serious problem....yet.....lets figure it out before you throw everything at it.

Is it easy to repot in same size pot?I imagine it as really root disturbing.I can't use bigger pots because there is not enough space in the growroom.

If you can't afford a $7.00 freswater aquarium ph test kit, you can google your local water quality report, which should have pertinant information about your local tapwater.
But Like Washougal said...please copy-n-paste the troubleshooting form here, and fill it in as best you can. (no guesswork...if you don't know, just say so)

I'm in a small town and finding cheap ph strips is not easy.Last time I only found in a pet shop and I payed 20â?¬ for 20 strips measuring ph and EC, I found my company's site though.I'm not sure from what source I'm taking but I lowered them to 2.So, PH: 7.75 for source A and 7.68 for source b.EC:433 μS/cm for A and 427 for b.

Your Equipment:
.1) Type and wattage of lights. Hps 400 watts
.2) Distance from tops? 45cm
.3) Reflector type? cool tube set-up
.4) Is there a consistent fresh air supply?I am using a pc fan of 110cfm for outtake and leave the closet doors opened, so passive intake.
.5) Do you have an exhaust fan and a circulation fan?A fan out the closet hitting the tops.
.6) What are the bulb wattages, kelvin ratings, and schedule?12/12

Your medium:
.7) Specific brand and type of soil.soil, slightly fertilized and added perlite (not much).I put some rocks in the bottom of the pots for better drainage.
.8) Size of container.13L
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings?No

Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting?Tap water of ph 7.7
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...)
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...)I am not adjusting
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule.Biogrow (8-2-6), Biobloom(2-6-3.5), Alg-A-Mic(0.1-0.1-0.1 + trace elements).Feeding every 10 days.Have fed them twice.First time Biogrow 0.7ml/L.Second time Biogrow 0.9ml/L and Biobloom 0.9ml/L.Today I fed them with Biogrow 1ml/L, Biobloom 1ml/L, Alg-A-Mic 1ml/L and 0.5ml/L of a ph down which contains 4-18-0..I think I overdid it on phosphorus this time.
14) How often are you watering between feedings, and how much per watering?About 2 times a week, 0.5L on each pot.
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...)No
16) Are your ph levels stable, or do they fluctuate?
17) What is your ingoing water's ph? ...your runoff ph?On regular waterings ph about 7.7
18) Do you foliar feed? If so, with what, how often, and at what time do you spray?No

Your growroom:
19) Indoors or outdoors?Indoors
20) What size of closet, room or hut?60cmx90cm.Height 160cm.
21) What are the temps and humidity levels while lights are on? ...With lights off? Lights on 27-29C, mostly 28.5-29C and hum 30% lights on.Temp drops to 20-21C lights off.
22) Have you seen signs of insects in the growroom?No, never had.

Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) One sativa dom, 2 indica dom and one 60%-40%.
24) From seeds or clones?Seeds
25) Is this an autoflower strain? No

[Salvein211]

I think Rusty and WW can give you better advice then I, but I will just say that yeah before you throw pH down in there, be careful. The main point of my post was that when you have pure water at a 7.3-7.7 pH or whatever have you, adding nutes drops it considerably. I know you said you havent fed much, so that could mean pH isnt the issue, but its something to look at. So before you know what pH levels you are dealing with, I wouldnt use pH down, because it was my idea that the pH was already too low after adding nutes to the water... pH down would just make it worse...

[Rusty Trichome]

Proper ingoing water ph, in peat-based soil, is between 6.3 and 6.8 if the soil is already properly buffered. You didn't mention brand or kind of soil, but check the bag to see if it says it's ph balanced. Since you mentioned that the soil is "slightly fertilized", it might be that you're adding too many nutrients before the existing nutrients in the soil burn-off. (get used-up)
Which specific brand and type. (Miracle Grow 6 month, Scotts 3 month, Fox Farms Ocean Forest, SuperSoil...?) Is it an indoor potting mix? Just curious, because outdoor mixes tend to be virtually unbuffered. (ph is too low ofr indoor cannabis)

My tapwater (from a well) comes out of the tap at 7.9ish ph. After adding 1/4 tsp of phDown per gallon of water, the ph is about 6.9ish. Adding nutrients to that, (Fox Farms) my ingoing water is at 6.3ish. Everyone's situation will be different, so do not use my numbers as a hard and fast rule, but as an example. Adjust to suit YOUR situation.

For instance, my water comes from an underground aquafir, through layers of magnesium/limestone bedrock. the minerals in my water want to keep bringing-up the ph. (I don't R/O my water) So my quantity of phDown might be a bit of overkill for someone else's 7.9 water that's unaffected by minerals.
Perhaps intimidating, but not really rocket science, lol.

Any of that make sence?

[stefanosstef]

I think Rusty and WW can give you better advice then I, but I will just say that yeah before you throw pH down in there, be careful. The main point of my post was that when you have pure water at a 7.3-7.7 pH or whatever have you, adding nutes drops it considerably. I know you said you havent fed much, so that could mean pH isnt the issue, but its something to look at. So before you know what pH levels you are dealing with, I wouldnt use pH down, because it was my idea that the pH was already too low after adding nutes to the water... pH down would just make it worse...

Yeah you're right, but I added ph down, just a little, acting by instict.I'm observing it carefully every some hours until I got my ph strips.