DWC ph related to PPM

Discussion in 'Hydroponic Growing' started by bizybily, Apr 14, 2015.

  1. [SIZE=medium]I have a DWC setup and I read that when your nutrients (ppm) are to high the ph will be low and if nutrients (ppm) are to low ph will go up. My res solution has been real low but I don't see any signs of nutrient burn. Can anyone elaborate on this? [/SIZE]

     
  2. No idea where you read that but I've never encountered that. Are you able to take a ppm reading?
     
  3. I mean what kind of water are you using first?  If you're doing a hydro grow, you need to be using reverse osmosis filtered water or distilled.....the ppm for that before you add nutes should be around 50.  
     
    If you're not seeing any signs of stress the girls are fine.
     
  4. I do ph and ppm readings daily. I am using rain water that is anywhere from 9 to 25 PPM. The girls look fine, no sign of nutrient burn but i'm using a ton of ph up to keep it at 5.8. I use GH flora trio with Hydroguard and cal-mag.
     
  5. What are your res temps?
    How do the roots look?
    Pictures?
     
  6. you shouldn't need to add anything to your res
     
    ph should stay consistent, with a slight swing, in between reservoir topoffs, if the ph is dipping constantly there is likely something wrong with your mix
     
     
    if ppm rises the solution is too strong
     
    if ppm lowers it is too weak
     
     
    if your ppm's are swinging this will cause ph to swing as well
     
  7. The 4 plants are in 5 gal buckets and are in the sixth week of bloom. Leaves are dark green, perhaps too much nitrogen. The roots and buckets have a light green color that washes off easily.
     
    This is the data I've kept since last res change: cups = cups of water added to res.  PH 1 and PPM 1 are the initial readings. PH 2 and PPM 2 are readings after water and ph-up are added to res.
    Today
    Date:     cups:     PH 1       PPM 1   PH 2       PPM 2
    4/12       res change                          5.8          690
    4/13       8              5.5          690         5.9          680
    4/14       16           5.1          702         5.7          638
    4/15       16           5.2          652         5.8          623
    4/16       16           5.8          636         5.8          625
     
  8. #8 hddani, Apr 16, 2015
    Last edited by a moderator: Apr 16, 2015
    If I'm reading your #s right, ppms are rising from ppm2 on day x to ppm1 the next day right? 
    I follow goldgrower's guide on honing in the plants preferred nutrient strength and based on that I would say the solution is a tad too strong; the plants are currently drinking more water than nutrients thus resulting in a more concentrated solution. 
    Of course this is based on that chart and I could be reading it wrong, just my .02. I'm also a noob but gg's guide is working for me.
     
    My WW auto currently drinks ~.5 gallon/day and at last top off & feeding ppms were at 650, after losing almost a gallon of water the ppm reading is at 625, indicating she could use a little more nutes cause shes feeding.  Tonight is top off and I anticipate even more water will need replacing AND a lower ppm reading so I'll bump her up to 700ppm, then repeat based on ppm readings. Hope this helps!
     
    p.s. got any pics of that green stuff that rinses off? It could be algae growth man bad stuff in hydro and may be whats causing your ph swing
     
  9. I used rain water my first time, it starts to stink pretty fast, whats the problem with your tap water?
    You probably have algae or pythium, try H2O2, 1ml per gallon every other day should clear that stuff.
     
  10. Hddani, I feel that sir! Ggs the man!
     
  11. Okay. I got my ppm stable but still having a drastic phdrop. I decided this morning to let the two plants go on their own so I pulledthe line from the res water pump but let the pump continue to pump. (justrunning back into the res.).
    At 7:30am The ph was at 4.7 so I brought one 5 gal. bucketto 5.9 and the other to 6.0. I also did the res to 6.0. By 10:30am both bucketswere at 5.2 and the res was still at 6.0.
    The temp in the res is at 71.4 and the buckets are at 74.8
    The plants look fine and the root zone is healthy and white.
    This is one of the two plants.
     

    Attached Files:

  12. Have you flushed your grow medium? Sometimes salt build up in the hydroton will do this.. I would use Clearex or FloraKleen to do a maintenance flush to leach out the salts. good luck
     
  13. Thanx Wiz. Gonna try that today
     

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