Please Help PH problem

Discussion in 'First Time Marijuana Growers' started by onlygradeA, Oct 18, 2011.

  1. hey guys can any1 help me out getting reallly aggravated. im 25 days since seed under 400wmh using FFOF in 3 gallon pots. OK, I watered last week with water phed to 7.2 and I got a runoff on average of about 5.6 then this week i feed at 25%and then phed to 8.2 on 2-3 of my plants my phed dropped a couple points how is this possible? What am I doing/not doing and how can I correct my problem.
     
  2. I would not worry about runoff. As long as the water you are giving them is ph'd correctly dont sweat it. The bennif. bacteria and micro organisms in your soil are going to change the pH but as long as the nutrient solution you are feeding it is correct the plant will absorb that nutrition.

    I keep a soil pH meter for soil grows and it works well. They are calibrated to read the pH of soil which is what you are growing in NOT the liquid. In other words, your soil pH and liquid runoff pH are going to be way different. Remember, feed the soil, then let the soil feed the plant.
     
  3. ok, but from what i understand FOF usually has ph a lil low so do I not want to bring that up a little
     

  4. I disagree. Just because you feed with water that is correct doesn't mean that the pH of the soil is correct, and thus what the plants will absorb. Runoff is a good way to check the soil pH.

    In any event, add dolomite lime to your soil. You want to get the powder kind (a hydro shop will have this). It is best to mix it in before you start growing, but you can still add it now. Just sprinkle a layer on the top of your soil and then water the plant. This will help the dolomite mix into the soil. The dolomite will balance out the soil; it will raise the pH if it's too acidic, and lower it if it's too basic. This approach is much better than trying to fight the pH by adding pH up and pH down to the feed water, and it will remain a lot more consistent. It will last for quite a while, and you should only need to add more dolomite one or two more times throughout the grow, if that. Good luck :smoke:
     
  5. #5 TheGreenLegend, Oct 18, 2011
    Last edited by a moderator: Oct 18, 2011
    I agree that the soil pH should be corrected but what Im saying is that the runoff is not a true measure of the soil alkalinity or acidity because the liquid you are pouring in mixed with the salts in the soil as it runs out is going to be different from that of what is actually in the soil. Thats why I use a pH meter made for soil as it measures the pH of the soil itself because soil conducts differently when read for pH than water does.

    But yes ultimately the ideal thing to do would be to amend the soil so the pH is buffered.
     
  6. Test the run-off, fix the run-off fix the problem :smoke:
     
  7. so the dolomite lome would be the solution
     
  8. #8 Bud Upinsmoke, Oct 18, 2011
    Last edited by a moderator: Oct 19, 2011
    Everyone has good points here but, .... test the soil! Why determine your ph from the run off or the water you add if it's the soil ph that matters. You can use the results from the run off and the water your adding as a guide but you need to start with a proper ph in your soil then ph the water your adding accordingly. You can get a soil ph testing kit for fairly cheap at any gardening store. Also keep in mind that any nutrients that you add will lower the soil ph.

    Also, Lime raises soil ph but does not lower it. So, it is not a fix all ... if you add too much then you will have too high of a ph.
     
  9. sigh, ok so if the soil ph is too low what do i do to raise and FIX the problem since lime is not gonna fix the problem
     
  10. #10 Bud Upinsmoke, Oct 19, 2011
    Last edited by a moderator: Oct 19, 2011
    No no, lime WILL raise your soil ph but you need to test your soil to determine what ph you truly are at. Testing the run off or added water will not help you ph the soil. (lime will raise the ph but NOT lower it)

    So basically if your soil ph is, say, 5.5. You would want to add x amount of lime to your soil to bring it up to around 6.5 - 6.8. Then, if you ph your water to 6.8 you will be golden.

    Now, if you add nutes then you have to take that into consideration, nutes will lower your soil ph by about .5. So, if you start out with a ph of 6.5 then add nutes you will be around 6.0 ... too low. I suggest adjusting your soil ph to 7.0-7.3 and ph your water to 6.8, this way when you add your nutes you should be right around the 6.8 mark. make sense? Also, since it is soil you will not be able to get it right at 6.8 and keep it there ... it will fluctuate .2 or so either way so don't kill yourself trying to get the ph exactly right ... leave that up to the hydro growers!

    EDIT: It looks to me like you might not have tested the soil ph before planting, if I am wrong then i apologize. Then it seems like you are trying to correct the issue with ph'ing your water. This is like putting a band-aid on a cut that requires stitches.... A good soil grow starts with the soil and revolves around the soil, if something is wrong with the soil then you need to address the soil, not the water going into it.
     
  11. #11 SSH, Oct 19, 2011
    Last edited by a moderator: Oct 19, 2011
    Dolomite lime will lower and raise your pH. It should not necessarily be used to lower however. Dolomite lime has a neutral pH of 7, and acts as a buffer to maintain that consistent level.

    Bottom line, use fine powder dolomite lime to fix your problem.

    EDIT: When I say lower, I mean only slightly to reach neutral (used it in my last grow for this). What Bud says is correct though; it can be used as a pH up, and then to buffer and maintain. Shouldn't be used as a pH down though.
     
  12. ok bud your absolutely right iI did not check soil ph. Did tons of reading on here didnt really see how important that was will be getting a soil ph kit tomorrow as well as the dolomite lime.Another thing bud is 6.8 is what I want my water to be at when my nutes are in my water correct?And if I only have to water once a week do I still follow water,water,nute,water,water,nnute. Arent I suppose to feed once a week?
     
  13. #13 Bud Upinsmoke, Oct 20, 2011
    Last edited by a moderator: Oct 20, 2011
    Yeah, if you mix your nutes in with your water then ph the mix to 6.8.

    Feeding is kinda a different story. Some strains like a lot of extra nutes where some don't like much at all. I have two strains growing right now, I can only add nutes to one of the strains once every two weeks or it gets nute burn whereas the other strain likes the extra feed once a week. So, Maybe do once every 2 weeks and make sure your not getting any nute burn and add more if the plant is thriving. If you are feeding once a week and the plants are thriving then I would let it be at that.

    EDIT: Also, like someone else said, get powdered lime. I believe it's called hydrated lime. The pellet or chunk lime will take too long to adjust the ph because they are intended for long term use.
     
  14. #14 onlygradeA, Oct 20, 2011
    Last edited by a moderator: Oct 20, 2011
    lol just got back from home depot with pelletized garden lime. The had another bag that said blend of calcite and pulverized dolomite lime. The bag I just bought says it spreads easily and reacts quickly and it doesnt pose hazards associated with hydrated lime w/e those hazards might be. Here is a pic of front and back should I keep or return? And another thing being that I only fed plants last feeding with 25% is it ok to feed again this week at 50% being last week wasnt a full feeding?
     

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  15. The hazards they are talking about is the dust from the hydrated (powdered) lime.... just need to wear a mask so you don't inhale it. Really, if you can return it and get the hydrated you will be much happier. The pellets are slow release so are more suitable for treating outdoor areas like around trees or regular gardens.

    Yes, it is a good idea starting out with a weak mix then step it up like your doing. Go ahead and try the 50% if your plants look completely healthy with no browning or yellowing on the leaves.
     
  16. ok thx uploaded pics of the bag I got, and do you use calmag with your grow as an extra additive
     
  17. i don't use calmag but I do use black strap Molasses throughout my grow. It has calcium, magnesium, and many other important minerals. When I apply it i add extra fish emulsion so it doesn't mess with microbe activity, which could result in malnutrition of the plant.
     
  18. I am hearing calmag will do the same thing the dolomite lime will do, is there any truth to this?
     
  19. #19 Bud Upinsmoke, Oct 20, 2011
    Last edited by a moderator: Oct 20, 2011
    As far as I know calmag only delivers calcium and magnesium, I don't believe it adjusts the soil ph like lime.

    Molasses, on the other hand, is the popular alternate to calmag. In my opinion Molasses is better because it has a lot more benefits for the soil.

    EDIT: If you cannot find hydrated lime there are other ways to raise your soil ph. Hard wood ash and egg shells are two that work.
     

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