Yellow w/brown spots, curling up tips. Small brown dots all over

Discussion in 'Sick Plants and Problems' started by splenetik, Nov 29, 2007.

  1. I have been battling this issue for about a week.

    These are 2 different widow plants growing in a 3 gal hydroponic system.

    The top pic (Plant 1), the problem is affecting the middle/lower, older leaves. The new growth looks good, but it kinda looks like it lacks some vigor.

    The bottom pic (Plant 2) the problem is affecting the top leaves.

    pH is 6.0

    I dont know what the ppm is, i just ordered the meter.

    I thought it was a magnesium deficiency, but 2tbs of epsom salt didnt do anything.

    The nutes are fox farm.

    Anyone want to take a stab at it so that i may have a starting point.

    Thanks...SpleN
     

    Attached Files:

  2. Drop to about half the nutes you currently use.
     
  3. What does the new growth look like?
     
  4. I don't know if you have looked at the sticky for diagnosing problems with your plant. It is called nutrients, bugs and various problems guide.

    http://forum.grasscity.com/sick-plants-problems/25983-nutrients-bugs-various-problems-guide.html

    It will usually diagnose your problems at least 90% of the time. Your problem appears to be described in detail.


    Leaf Problems

    Yellowing (Chlorosis) - Chlorosis is a yellowing of leaf tissue due to a lack of chlorophyll. Possible causes of chlorosis include poor drainage, damaged roots, compacted roots (see Root Bound below), high alkalinity, and nutrient deficiencies. Nutrient deficiencies may occur because there is an insufficient amount in the soil or because the nutrients are unavailable due to a high pH. **Note- Always check the pH before increasing nutrient level. In the last few weeks of flowering a yellowing of the leaves is completely normal as the plant uses up all stored nutrients.


    Yellowing - Lower/Middle Leaves - Yellowing of the lower leaves/older growth is a sign of a possible Nitrogen (N) deficiency. Nitrogen is a transferable element (this means the plant can move it around as needed). If a plant is not receiving enough Nitrogen from the roots then it will rob Nitrogen from the older growth. Plants that are Nitrogen deficient will exhibit a lack of vigor and grow slowly resulting in a weak and stunted plant that is significantly reduced in quality and yield. In a Hydroponic system, usually the pH is too high and has locked out the available Nitrogen. In soil a yellowing of the lower leaves could also be an indication of a root bound plant (see Root Bound below).

    Solution - First, check the pH, and adjust if necessary. The correct pH for marijuana is 6.3 - 6.8 in soil and 5.5 - 6.1 in a hydroponic system. Second, make sure you are giving the correct amount/type of fertilizer/nutrients. For the vegetative stage of growth marijuana needs a fertilizer/nutrient with a high Nitrogen (N) content like 2-1-1 (or 20-10-10).


    Yellowing - Upper (New Growth) - Yellowing of the upper (new growth) of the plants could be a sign of a Sulphur (S) deficiency. Sulphur deficiency is pretty rare but usually start off as a yellowing of the entire ‘younger' leaf including the veins. Other signs of sulfur deficiency are: Elongated roots, woody stems, and Leaf tips curling downward. **Note- Most yellowing of the upper leaves is a bleaching from being too close to the lights.

    Solution - Check and adjust the pH level as necessary. Check your fertilizer/nutrient levels and make sure you are giving the correct amount/type for you particular stage of growth. Also a good test to see if your lights are too close is to put your hand between the light and the plant. If your hand gets too hot for comfort, the light is too close and needs to be moved up higher.


    Leaf Curling Up - Leaf curling up can be a sign of a Magnesium (Mg) deficiency caused by too low of a pH level. Magnesium deficiency will show as a yellowing (which may turn brown and crispy) and interveinal (in between the veins) yellowing beginning in the older leaves. Interveinal chlorosis (yellowing) will start at the leaf tip and progressing inward between the veins. It could also be a sign of excess heat and humidity in the grow room.

    Solution - Check and adjust the pH level as necessary. When the pH is not at the proper level marijuana will lose its ability to absorb some of the essential elements required for healthy growth. If you're growing in soil Magnesium will begin to be locked out at a pH of 6.5 and lower, in hydro it starts at 5.8 and below. If the pH is correct, then add 1 teaspoon of Epsom salts per each gallon to your water. Or, to foliar feed them, add a ½ teaspoon per quart to a spray bottle. **Note- If your tap water is over 200 ppm Magnesium will be locked out due to the calcium in the water. Magnesium can get locked out by too much Calcium (Ca), Chlorine (Cl) or Ammonium Nitrogen (NH4+). If this is your problem we suggest using bottled or RO (reverse osmosis) water.
     
  5. Here is a good starting point, lower the pH to 5.5. Your 6.0 is out of range.
     
  6. The new growth on plant 1 is green and lush, but the new growth on plant 2 looks a little crispy, but green.

    I lowered my nutrient level.

    According to that scale it looks as though its magnesium, but i tried that already.

    It is still only in the middle, on plant 1 and all over on plant 2(just brown spots, no yellowing)


    -SpleN
     
  7. splenetik please check out this link http://www.ganjaguerrilla.net/
    Click on pH related issues. The first picture shows a leaf identical to yours. Your problem is pH.
     
  8. its has been at 6.0 pH for days now, where should it be at?

    -SpleN
     
  9. i definetly think its an excessive amount of nutrients your supplying to them. Widow is extremely touchy on nutrients. I have some blueberry now and the foxfarms with the grow big is giving me problems even with a different strain. Id say dont start ur widows in ocean forest unless u wanna be battling against a stunted young one. get some happy frog, works wonders with the widow and use about 1/4 of a cap full of grow big after about 2 - 3 weeks. Guaranteed to generate perfect plants similar to my avantar. :rolleyes:
     
  10. Thank you!!!

    I just got my meters and the pH is 6.3 and the tds is 2800, which if i am not mistaken i am killing them with toooooooooooooo many nutrients. So I would say a flush is in order.

    what should the tds/ppm be?


    -SpleN
     
  11. Ok, basic hydro targets...all of these are important

    TDS depends on lighting -
    If under HID then you're aiming for 950 @ 0.5 or 1330 @ 0.7 conversion
    If under flouros then 600@0.5 or 830@0.7
    *the numbers are based on the Lucas Formula, but I believe that other formulas are similar - also, make sure your using a nute profile designed specifically for MJ or you may have the wrong balance of nutes.

    pH needs to be between 5.5 and 5.8.

    Temps - Res temps should be between 65F and 70F, ambient temps should be around 75F during lights on, although they can go higher as long as your res stays cool enough.

    It sounds like your reservoir is pretty badly out of wack. I'd drain it and refill with a fresh batch of nutes.
     
  12. It is best to stay with 1 thread so everyone doesn't keep repeating the same crap over and over and that is exactly what is happening so far. Both tenacity and smokn gave you excellent advice in this original thread. Like I told you before, no matter how many threads you start, you need to try some of the suggestions. Tenacity told you that using ocean forest was going to give you problems and he is familiar with fox farm, im not. Smokn says it is a ph problem and that is what looks wrong in the pics.

    Personally I have no desire to be repeating things in several threads for a single problem. People need to be able to see what has already been tried and suggested. This is the 3rd thread you have started about this.

    good luck dude. maybe someone has an answer for you that you might actually listen to or whatever answer you are wanting to hear. Smokn is a top grower. It might be a good idea to reread everything he has said. Look at what others have told you and try them.
     
  13. flush plants for 3-5 days. Will be easier to asess problem then
     

Share This Page