pH runoff extremely low

Discussion in 'Sick Plants and Problems' started by infiniteuse, Sep 22, 2009.

  1. Hey guys. I have three plants into 18 days of flowering. They started from seed and vegged for 30 days. Here are my specs:

    Age: 48 days
    Closet grow: 4x6x8
    Light: 400w HPS
    Soil: FFOF
    Temps/Humidity: 80-82F / 30-40%
    Tap Water Ph: 6.6 - 6.8
    Fert: Tiger Bloom (every other feeding, changing to once a week starting now)
    Strain: Nirvana Northern Lights x2 / Dinafem Blue widow x1

    My problem started when I noticed the bottom fan leaves on my plants started to show signs of nute burn. Burnt tips, edges, and slight yellowing. So I decided to give them a flush. They are in 10in pots, which I'm guessing are roughly 3 gallons each, so I used 3 gallons of pH adjusted water (6.8) for each plant. I let the plants drain for a bit and decided I should collect some of the run off water which came out to be at least 4 or 5. I added another gallon to each and tested the run off again. Came out to be the same. I did this a couple more times, but the pH never went up.

    Does anyone have an explanation for this and advise on what to do? Thanks in advance!

    Oh and BTW, I'm using a liquid based pH test kit from an aquarium store.
  2. Top dress dolomite lime and water it in...just a regular watering, no or little runoff.
  3. ditch the ph kit and get digital one imo
  4. Thanks guys, I'll look into the dolomite lime. This is my first grow so I didn't think a digital pH meter would be TOO necessary, but I'm most definitely going to invest in one after battling with pH every other day.
  5. yes mate i thought exactly the same till i ran into ph issues ive sinse learnt get your ph to 6.5 in soil and alls good imo lucky mistergreen :D

  6. a good digital meter cost 200 bux in some cases.

    my hydro shop says he tests his 230$ ph meter with a liquid based test kit.

    liquid based test kits are extreamly accurate. the colors are completely different from each ph level. its very obious if its yellow or green ya know?

    i recomend flushing with higher ph water. 7 or so. and see if that helps

    i had same issue. my ph wouldnt move from 8. so i used 5.0 water and volla. i got 6.5 soil.

    fox farm soils have ph adjusters in them and they work pretty darn well. i'd call the company and ask whats up if at all possible

    also make sure when you use tap water you let the chlorine burn off. test the water before. and test the water after 24 hours of sitting with lid open. compare the results!

    so all in all maybe you should just go buy 6 gallons of spring/distilled water. set you back 6$ and have at it. that water is ph nutral of 7 in most cases:hello:
  7. ha ha ha i love a good debate so here goes

    my hydro shop says he tests his 230$ ph meter with a liquid based test kit.
    lets get this rite are you talkin about the $5 kits that you either put soil or run off water in the container add the powder and water and shake and see wot colout it goes ?
  8. I just went through this exact same thing.

    I was instructed to run 4x whatever the pot size was. In other words, 3 gallon pots get 12 gallons of water but as mentioned above, you spike it high to combat a low.

    I gradually added the ph up to the water till I hit max strength around gallon 7 (max strength was about 7.5) and slowly added less and less to the water till the last 2 gallons were straight water.

    Bingo, back on track, 6.8

    Make sure u have 3g pots, 10" doesn't seem right. My 3g are 12" diameter, your's might be 2 or 2.5.

    Good Luck!!

  9. no, its 3 solutions, one ph up, one ph down and one ph test solution. its not powder in my case.

    today i went to the hydro store and i asked them to show me how the meter works compared to my test kit. his 230$ meter corresponded with my color chart and the color of the water i shook in the lil vile.

    i dont see any debate. the debate should be on the quality of the ph test solution and your own eye site. yellow is 5.5 orange is 5.0 yellow green is 6.0 and dark green is 7. 8 is blue... its pretty damn obvious. considering i shoot for yellow with a hint of green to it.

    so i put the test to this theory and found that my ph kit is infact decent enough to check run off of soil.. hydroponic growers should not rely on this test kit alone because they need to know more then just the ph... ya know?
  10. ha ha ha no debate eh ? your just shootin straight facts eh ? well sorry i disagree a £230 ph meter is far far far superior than any crappy £10 test kit you can t be serious surly ? i used one of these test kits you talk about at the start of my first grow the colour was green/yellow for 6.5 ph i had all sorts of problems and it turned out to be ph after buying a digital ph pen £45 and checked my ph i was watering with ph 7.4 i corrected this and my grow turned out fine without ph probs again.........also this is his first grow arn t we here to make it fail proof wot we advise here so he doen t face the same issue twice ? all i can say my digital ph pen reads from 4 ph in point 0.1 fractions to 9 no colors no wot shade is this ? just true hard fact i also use it with ph buffer 4 so switch on the pen drop into the ph 4 buffer and if the pen reads ph 4 then its calabrated if it reads 4.5 then you just recalerbrate it accordingly fool proof system imo......enough said on the matter i bet the guy was sorry he asked ha lucky mistergreen :D
  11. He's not saying it's just as good, he's saying that for a soil grow, those kits are adequate to test run off. No need to drop big $$ right now. If you have the money, sure but for now, the kit will get u through the crisis. He would not give the same advice for any grow, especially hydro but for this case, I agree
  12. Truth...
    Yall quit bickering. Digital is good...great in fact, but his test kit is fine for us simple soil growers.
  13. #13 infiniteuse, Sep 24, 2009
    Last edited by a moderator: Sep 24, 2009
    Nice discussion here guys/gals, very interesting. Anyways, a few days have passed since I flushed and I am not seeing any more recurring signs of nute burn so I hope the problem has went away. Next time I water, I'll be sure to test the run off and report back in.

    I can see everyone's point they are trying to make, but I do think it would be in my best interest to get a digital pH meter in the near future. Besides the fact that I would like to get readings as accurate as x.01 and determining 6.2 - 6.8 is a pain, I just hate the whole pouring, mixing, shaking, pouring, mixing, shaking process!

    Also, one interesting thing I noticed that I failed to mention was I have two different strains going. Two Nirvana Northern Lights and one Dinafem Blue Widow. The runoffs of the Northern Lights were the ones that were sub pH 6. The Blue Widow was in normal range. Now, I do have a slight bias toward the Blue Widow, but could it be possible that some strains pull up more nutrients than other strains? I have been using the same feeding schedule for all three plants.
  14. hi mate glad everythings back on track.......check the first few trickles of water for run off test gives a more accurate reading.........going with the digital pen i think is the safest route also ask where you buy the digi pen for a solution to drop the probe of the pen in whilst not in use im sorry i forgot wot its called but it will give you lot more life outta the pen..........yes i agree some plants take more nutes than others just wondering is the reason your trying to get 2 different ph reading coz of the variation of ph in both plants ?....ok hope this lucky mistergreen :D
  15. And if this is the cause, the deterioration is exponential. The plant gets low ph from too much nutes (for that particular plant, the amt used was fine for the others) so it begins to lock out. Now with lockout, the nutes you put in only get accumulated further, making the ph continue to drop but faster and harder now.

    Good food for thought.

    Glad all is well now, that's all that really matters, but some learnin along the way never hurts :)

    I'll have my ph pen eventually but I know better than to buy the one I can addord right now. Being in soil, I don't NEED it as badly s others but I WANT one just the same so it's only a matter of time

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