Deep Water Culuture Ppm Advice Needed

Discussion in 'Hydroponic Growing' started by DeltaIX, May 29, 2013.

  1. I've recently started to convert from ebb and flow systems to DWC systems.  I curently have one Current Culture 24 site recirculating DWC system along side my ebb and flow.  While I am amazed with the explosive growth, I am struggling a bit with nutient levels. I could not find much info on DWC ppm so i first tried my standard ebb and flow regiem.  Rapid growth turned to rapid and irreversable over fert. Even when I brought levels down from 1200pmm to 700ppm the damage was done and i suffered reduced yield and quality.  One week into a new flowering cycle and im now running approx. 500ppm.  Growth is rapid but i see new growth pointing sharply upwards. This happened last grow.  I thought it was a good sign but later found it to be the first sign of over fert.  Feeding charts for hydro systems are all over books and the internet but with regards to DWC the only info i've found seems to be the very nonspecific "use much less".
    Please share with me expiriences and what ppm schedule works for you.  I know this type of system is just recently becoming popular (with the obvious exception of the home made bubble bucket) so info on what did NOT work would also be usefull.

  2. the plants will only take what they want. that goes for amount of nutes amount of water and ratio of all of them.

    so, what you want is to provide the same ratio as the plant is currently using at any given time. a good ratio of nutes can be provided by using a cannabis designed nutrient brand and change the solution on a regular bases

    to find out their preferred ppm you first need to make up some solution and test it. then wait 24 hours and test again....

    if the solution has gotten stronger (ppm goes up) it means the plant has been using more water and less nutrients so that means your original ppm (24 hours ago) was too high. so add some water to bring it down and test again

    if the solution has gotten weaker (ppm goes down) it means the plant has been using more nutrients and less water so that means your original ppm (24 hours ago) was too low. so add some nutrients to bring it up and test again

    if you test it after 24 hours and you can see that some of the nutrient solution has been "drunk" but the ppm has stayed the same you know the plant is using them in the same balance as in the reservoir and you have it spot on.

    if the solution is too strong it will draw water out of the plant via osmosis slowing uptake dramatically
  3. I have followed the "goldgrower formula" for some time now and I don't get over or under dose issues at all
  4. Wow!   You know, that's probably one of the first things I learned about hydroponic feeding.  I guess over the years I've gotten too deep into the technical that I didn't step back and see the obvious.  When I just read that I thought "duh".  Thanks for the reality check.  But 500ppm is really low.  What do your DWC's usually run?
  5. they can go up to an EC of 1.2, usually up to about 0.9 in veg, I'm not sure what that is in ppm, but 500 does sound pretty low for a well established plant
  6. I found a conversion table, what brand is your meter?

  7. I use Blue Lab Guardian Monitors.  They have the ablity to display nutrient concentration in 4 different scales.  My current reading is: EC=0.9,  CF=9,  TDS=440(ECx500),  ppm=610(ECx700).  I attribute the rise in concentration to the fact that it had been very hot in the room and co2 is temporarily out of comission so they're really thirsty to stay cool.  Today was the first day of high temp. and no co2 and that should be resolved tomorrow.  I know that ppm is terrible to go by.  Even nute companies get 500 scale and 700 scale mixed up when you speak with them.  I intend to go by EC from now on, it's just a pain in the ass to convert because my brain is used to thinking in ppm 700, but I guess it's just like speaking a new language.
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  8. Veg or flower I never go over 900 PPM.
  9. my nutrient bottles state a maximum of 2.0 EC, but if I ever had my solution that strong it would wipe out my plants straight away

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