Runoff ph and ppm high

Discussion in 'Coco Coir' started by 967, Jan 13, 2012.

  1. I have 8 fairly large plants 3 1/2 weeks into flower in coco/perlite and when i check the run off
    the ph and ppm levels are higher than what i feed with.. what does this mean?

    I've read before run off means nothing in coco possibly due to build ups of K and Ca?
    Well that didn't stop me checking and now wondering why its higher. Should it not be lower or at least the same for both?

    I feed between ph 5.5 and 5.8 (usually 5.7) at 1000 ppm with around 30% run off. The run off ph is 6.4 1400ppm is that normal?

    Plants are looking great, no deficiencies or anything i just wanna understand whats really going on and rather than just dumping
    nutes on them and hoping for the best

    • Like Like x 1
  2. #2 SCMC, Jan 13, 2012
    Last edited by a moderator: Jan 13, 2012
    You're over feeding them. This is buildup.

    The actual ppm in the media is likely even higher than 1400ppm.

    I am perplexed as to how your plants look good at 1000ppm. You must be using a meter that has a 700 conversion rather than a 500 conversion. Because, you see, ppm doesn't really tell anyone anything specific unless you include the conversion factor. Or, you could talk about the EC your conversion is based on and then everyone is on the same page.

    But, assuming a 700 conversion, that means you're running a solution of around 1.43ec, which for around day 25 is pretty sound and about what I'd be running. But if the runoff was at 2.0ec then I'd definitely start to worry.

    I'm surprised this isn't sort of obvious but... if you are washing out elements from the media then you are probably over feeding the plants. The residual food is being washed out as it has built-up in the media. This is, by definition, build-up and the precursor to nutrient issues. You're not way off though, with a 1.4ec feeding I'd allow up to a 1.85ec runoff. So... Just use a 1/2 strength solution and get maybe 50% runoff collected and bam, buildup is removed and you're plants will continue to stay happy.

    Coco is a media that tends to retain elements over time. With most coco nutrient systems, plus calcium supplementation, the excessive levels of calcium that are necessary to fill the cation bank when the media is "unconditioned" and the plant is vegetating are no longer needed once the media has built a cation bank and the plant is transitioned to flowering. Typically this coincides to the full transition to flowering when the plant itself needs less calcium. So, as the media requires less, and the plant requires less, we still continue to drop in a high Ca nutrient solution. These calcium ions can then interfere with the uptake of other cations like Magnesium and Potassium. Although the scale has not been tipped completely (or perhaps the issues have not presented yet) it appears that the solution you have been using is imbalanced for the particulars of your phenotype and the maturity of your media. Given that we're talking about coco I am just going to go out on a limb and assume that it's a touch too much Ca in the mixture these days. Do what you can to reduce that element while increasing Magnesium and Potassium, all while trying to keep your runoff EC within 30% of the solution EC, and I think that your plants will continue to be healthy and productive.

    Fail to get your runoff EC down and to continue to feed increasingly higher levels of the current solution will likely result in some form of deficiency sooner than later.
    • Like Like x 2

  3. good info but which is it .45 over or .30 over?:confused:
    and its ashame that ur not communicating with me:(:smoke:
  4. great post! i check my runoff #s (ph/ppm) every single time i water/feed. who ever says runoff #s with coco mean nothing knows nothing about growing with coco. i like reading posts from SCMC as he definitly knows what he's talking about.
    • Agree Agree x 1

  5. I'm using a hanna combo meter, not sure of conversion, whatever they come standard with. I only moniter ppm to give me an idea of the concentration of nutrients. Not sure why by EC seems more complicated to me. Anyhow, i'll start to moniter EC instead

    It is somewhat obvious i'm over feeding, however i was a bit reluctant to reduce the amount as i have no sign of deficiency except a slight nitrogen deficiency on my super bud strain (5 strains total all on the same schedule, not ideal but im not up to tailoring to 5 dif strains just yet) all other strains look just fine. I haven't tested each plant but the ones i have tested have generally around the same runoff.
    The other reason is im using just H&G A+B, no calmag so i thought the higher concentrated solution would help out there

    Anyway i guess ill take your advice and give a feeding at half strength, 50% run off then what back to 1.4 EC? Just one half strength feed or two or three? What should my run off be in relation to my nute solution? what is the cause of the PH rise of my runoff?

    Thanks for taking the time to reply, you sound like just the person i need to be talking to
  6. One other thing - I feed them every second day regardless. The only plant that really NEEDS it due to the media being a little dry is blue widow and she's f'n huge with fat ass nugs. Weird seeing as it has a reputation for low yield its outperforming the shit out of white widow, #1, super bud and sour candy so far.
    Should i perhaps be feeding the rest every third day instead of every second?
  7. hanna runs on the .5 scale. so your running like 2.8ec which i personally think is extremely high.
  8. Im also getting into the same areas of ec and runnoff.How do you like the hanna combo meter..Thats actually the model i plan on ordering this weekend.

    And yea from what ive been reading i would be check the EC.
  9. #9 967, Jan 14, 2012
    Last edited by a moderator: Jan 14, 2012
    uff that does sound extreme.. how could they not be feeling that burn? i do let the water sit and empty it weekly so i guess water would be evaporating possibly pushing those numbers up?

    What do i do now water at 0.8 EC a couple of times then slowly bump it again?

    As for the meter yeah its great. Before using it i was just using a generic cheap ass chinese ph meter which spat the dummy on me. Get what you pay for. I couldnt find anything as good or better quality for a similar price so went with the hanna. Guess thats why so many others do too

    I'll post some pics up in the morning when i water. This has me really confused now if i'm overfeeding the hell out of them at 1000ppm cos this one time i mixed nutes wrong and got 1450ppm (hanna meter) and thought rather than watering it down ill just feed them extra strength. Not one noticable negative effect at all. Guess that could have contributed to the build up but just seems strange im growing 5 different strains all on the same feed and not one leaf burned or twisted. If anything maybe a little too much nitrogen as they're pretty lush green. Other than that to me they look just fine..
  10. #10 SCMC, Jan 14, 2012
    Last edited by a moderator: Jan 14, 2012
    There was once a time when I had these great looking plants. Just killer.

    But would you believe these plants took 6 gallons of runoff just to get the EC under 3.99 to a place where my meter could read it. This was right when I got into reading my runoff EC and starting to understand what coco needs and what plants like. Before getting my meter my coco plants would usually look like balls at the end of flowering and now I understand why, I was over feeding them the wrong stuff, and doing so blindly.

    The end results of these once lush looking girls due to the high EC was this, a dismal harvest.

    It has been my experience that the EC should be watched closely as it washes from the media. The pH of the runoff has been buffered by the coco and will not resemble the solution EC anymore (don't worry about it, my runoff is usually around 6.5pH). Since the issues are somewhat slow to present themselves it is important to never let the media get away from you.

    Personally I alternate full strength and half strength feedings all the time to keep my runoff EC down around what I am feeding it. There are a lot of schools of thought on this matter and I suggest you just watch your runoff and employ a 1/2 strength rinsing whenever you notice a steady climb over a few feedings. For me, runoff EC is king in the grow room and basically determines what I feed and when I feed it. Another tool I use is to calculate my ppm levels from the labels to get a baseline for how to mix my solutions. The combination of watching the EC levels and calculating the ppm ratios has been the greatest improvement in my own garden.

    I am not telling you to change anything really. Just watch you levels, keep your runoff EC reasonable with a rinse and some runoff, and don't fall into the habit of thinking that just because the plant looks great today it will continue to look great tomorrow. Requirements change and it helps to recognize those changes before the issue erupts.

    Attached Files:

    • Like Like x 2
  11. #11 967, Jan 14, 2012
    Last edited by a moderator: Jan 14, 2012
    Wow man, i'm not happy with the size of my buds right now bar one or two plants and now i guess i know why. I thought coco was keep increasing the feed amount until you see burn then back off a little and keep it at that. Didn't realise there was so much to it. Only reason i went to 1000ppm is because of that reason. when i bought H&G nutes i got a feeding chart with it which advises 1400ppm during early to mid flowering, although i know not to feed full strength i thought doing so once wouldn't hurt it and it was mostly curiosity that got the better of me

    My last grow (soil) was crap so because i can see no problems now i thought i was just cruising along, getting ready for a great harvest with this one. Now im paranoid i've screwed it up and thats why i'm not getting the results i expected

    Once read "feed with every watering, water every second day and you cant go wrong" so thats kinda the policy i adopted

    Am i better off feeding when they start to get dry instead? Should i flush it with a low strength solution to under 1.8 EC runoff then alternate between 1.4 EC and 0.7? Extra runoff at 0.7? Bearing in mind i'm using simply H&G A+B, no additives at all..

    As for your plants in the first pic, mine used to look like that with a lower strength feed, i thought it was sulphur def. so fed epsom salts and kept upping the dose and eventually balanced itself out. I'll throw pics up in the morning cos once again, i'm paranoid..

    cheers man, i'd hate to screw it up now as i thought i was in for a bumper crop!

  12. heres some pics of these bitches i've been nuking. Now that i'm actually looking for it i can see a very slight twist on some of the leaves

    Feed at 1.0 EC this morning. Was aiming for a bit lower than that but thats a significant drop compared to what they're used to. Next time i'll empty drip trays and mix it to 0.5 EC then check runoff

    First pic is of a fairly large white widow, second pic is sour candy and the third pic is of the smallest plant in the room, another white widow..

    Attached Files:

  13. Yup. They look fine to me. Just the slightest hint of nutrient burn on a handful of leaf tips, but nothing to be concerned about in the slightest.

    I really don't think you have any problem to address. Just something to keep an eye on.

    The 1.0ec feeding should do the trick to keep the runoff EC from getting away from you. Don't do anything extreme (like rinsing again with 0.5ec). I think that you could alternate the 1.0ec and your regular strength for a little while and just watch the runoff. Things should stabilize in a few days and you'll be gearing up for a pre-harvest flush here in no time.
  14. awesome man, growing in coco has been such a dream i'd be heartbroken if i f*cked up now

    By alternating between half strength and my regular feedings do you mean my 1000ppm which would be pushing 2.0 EC? or lower?
  15. If it ain't broken...

    I mean, I have no idea how your plants are healthy at the current nutrient levels but I guess we can chalk it up to House and Garden's nutrient system somehow.

    I don't want to lead you astray here and tell you to change something that is obviously working. There is the chance, and I mean "chance," that you are starting to get some buildup in the media from the high feedings. I don't think you need to be scheduling your lower strength rinses in advance. Stick with your 1000ppm solution (if you think it isn't a bad idea then who am I to argue) and just watch your runoff. When it seems like after 2 or 3 feedings that the runoff EC keeps going higher and higher then it would be a good idea to employ a rinse.

    If the EC isn't getting higher and higher then you could just keep feeding what you are.

    Watch the runoff. That's the stuff that will really tell you what to do. From way over here I don't think I want to suggest any sort of dramatic change from how you have been doing it. Just be careful, understand you are using the upper echelon of the ppm range in coco, and watch that runoff.

    The minute those plants head south, and I am not saying they will but if they do, then you know right where to go and just what to do. 1/2 strength rinse, Epsom Salt foliar, and back on the program.

    A lot can happen in 5 weeks too dude. Your flowers have plenty of time to pick up a little beef.
    • Like Like x 2
  16. My hydro store dude told me it's nearly impossible to burn plants with H&G nutes. I guess he was right, lol.

  17. True that man. I actually thought i was under feeding them at 1000ppm :eek:
    They recommend 1400ppm/2.0EC at this stage of flower. I thought H&G would use the same conversion rate as Hanna so i never bothered to check EC (such a stupid and easily avoidable mistake) Anyway no real harm done thanks to H&G i guess

    And thanks to you SCMC for all the advice :)
  18. So i feed again today at 1.0 EC, checked run off and its somewhere in the 1.8 - 2.0 EC range, depending on the plant

    So am i good to keep feeding 1.0 EC until it gets down somewhere around 1.4? Are they likely to show deficiency doing this? Should i increase it 0.1 EC each watering until i get up to 1.5 ish?

    On the plus side i had to stake my blue widow today :cool: Buds aren't exactly enormous but they're big, and she has spindly little arms that cant quite hold them up anymore :D
  19. so if I understanding this correctly.

    Goal is for the runoff to be around the same as what you put in ?
  20. can anyone tell me what the pH value should be from the run off? i mix between 5.5 - 6.0 and i just done my first run off test and between my 4 plants its 6.2, 6.3, 6.7, 7.0?!?!?! i'm now 5days into flower and the plant with a pH of 6.2 is taller than the others but looking like showing some signs of mag def or nute burn.......... any ideas?
    sorry if i'm being an idiot its only my 2nd ever grow so i'm pretty new to this and don't understand ppm and ec...... my tester only reads pH

Share This Page