DIY Hydroponic Nutrients in 5 minutes

Discussion in 'Do It Yourself' started by churchhaze, Dec 29, 2015.

  1.  
    churchhaze

    churchhaze Well-Known Member

    High ammonium is correlated with glossy claw leaves. In soil it's fine to get the majority of your N in urea/ammonium form, but in hydro, you want the majority of N to come from nitrates.
     
    Yesdog and rkymtnman like this.
  2.  
    Yesdog

    Yesdog Well-Known Member

    Yea normally the soil life gets to it first, probably why the plants suck at managing it- normally just doesn't happen.
     
  3.  
    SLITLOS

    SLITLOS Active Member

    As to your OP and I think your 3rd reply, No Cu, do you not use Cu?
    In my food nutes, I only use .500g for 1,000L. I use chelated Cu. Thanks
     
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  4.  
    churchhaze

    churchhaze Well-Known Member

    I've never bothered with adding Cu. I figure my pipes are made of copper so it hasn't been a problem.
     
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  5.  
    SLITLOS

    SLITLOS Active Member

    Thanks, I live in the #3 city in the land of sticks, the only C is in PVC, I do have Cu
    tubing in my AC.
    SLITLOS
     
  6.  
    The_Enthusiast

    The_Enthusiast Active Member

    Great thread. I love seeing Greenhouse grade talk here. But when you go mixing your nutrient route you really cant use NPK ratios anymore per say.
    Next step would be talking about everything in PPM (ppm per element not to be confused with conductivity ppm).
    Here is my formula (i use tap water that has 0.3 EC)
    [​IMG]
    and the nutrient compounds I mix:
    [​IMG]

    The Micro Combi is from HAIFA, and Potassium Silicate is 34%

    As you can see I give my plants 13 different elements (i would like to get Ni but didn't find it yet to add little)
    When I add everything I get PH 5.85 EC 1.95 and I use this formula from 1st day of bloom to 63/70 days (depending on strain)
    I have a big reservoir but i change it every 2 weeks. I would like to lower N but still didn't finish RO water on this location...
     
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  7.  
    churchhaze

    churchhaze Well-Known Member

    If you were american, I would suggest getting your Ni from a US nickle. (75% Ni, 25% Cu). 1 Nickle would last forever.... but I honestly see no reason to add Ni.

    As you probably realize from your own experience, the plants do fine without adding a source of Ni.

    I currently get all my zinc by drilling holes in a post 1982 penny, which is zinc with a copper shell. Yes, I should probably get zinc sulfate or zinc EDTA, but ....
     
    Tim Fox likes this.
  8.  
    churchhaze

    churchhaze Well-Known Member

    I don't see why you'd want to lower N from 138ppm. 87ppm is also pretty high for P so I can't see why you'd want to lower N : P ratio even more. Those look like good levels of Mg, Fe, B, and Mn. I have a feeling that people at higher ppfd are bottle-necked by their iron in particular and would do better with levels closer to 5ppm than 1ppm which is more commonly seen in commercial formulas..
     
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  9.  
    The_Enthusiast

    The_Enthusiast Active Member

    Ni is used by Nitrogen Fixation plants for that process. (this is a nitrogen fixation plant)
     
  10.  
    The_Enthusiast

    The_Enthusiast Active Member

    I want to have 100N not more. At the moment its 138 because I need to lower PH a lot after Potassium Silicat.

    Phosphorus high feed is 100 so it's still under high feed. I tried on few batches having [email protected] but the plants did have some light problems (after all they had 130 ppm of P for 70 strait days)

    EDIT:typo
     
  11.  
    churchhaze

    churchhaze Well-Known Member

    You could just replace the potassium silicate + nitric acid to balance it with potassium nitrate and then you wouldn't have to worry about glassifying your plants!
     
    Tim Fox likes this.
  12.  
    The_Enthusiast

    The_Enthusiast Active Member

    I'm cornered at the moment because I don't have RO water. Tap water has two much PH+ stuff in it so I'm countering it with a lot of Phosphoric acid and had to even add Nitric acid after introducing potassium silicate, and it was a nightmare to obtain potassium silicate...
     
  13.  
    churchhaze

    churchhaze Well-Known Member

    I have to use a lot of nitric acid myself because of hard water. The reason I didn't post my own recipe is because it's tailored to harder water than usual. Almost half of the calcium in the formula I'm using now comes from the tap water and a great deal of the nitrogen comes from the pH down.
     
  14.  
    The_Enthusiast

    The_Enthusiast Active Member

    Did you try lowering your PH with sulfuric acid? It it said: "Unlike most nutrients, plants can tolerate a high concentration of the SO2−
    4, selectively absorbing the nutrient as needed."
    And you can have it in 50-1000 ppm range as long as you don't cross overall osmotic pressure of you nutrient solution/plant.
     
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  15.  
    churchhaze

    churchhaze Well-Known Member

    I do use a little bit of sulfuric acid sometimes if the pH rises after a few days, but like I said, I rely on the nitric acid for N when using my tap. My base nutes have about 50ppm of S. I also worry about sulfate levels getting to high and causing P to precipitate out. My P is at ~60ppm, which I've always considered on the high end. (I never see recipes higher than that)
     
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  16.  
    Yesdog

    Yesdog Well-Known Member

    Sulfuric and nitric acid should be the best when dealing with tap (nitric a little better). The plants can deal with sulfates/sulfides pretty easy, but nitrates antagonize (solubility/availability) Mg and Ca far less. Switching to sulfuric acid fixed almost all of my pH bounce-up issues. Once I have a safe place to store some concentrated nitric acid, I'll switch to that (the diluted nitric acid is way too cost-prohibitive on its own) and just make my own stock 10% solutions.

    As far as cal/mag, the solubilities are magnitudes worse with phosphates and carbonates, then sulfates are better, and then nitrates the best.

    (units are g/L I believe, all at 15 deg C)

    Calcium nitrate 121.2
    Potassium carbonate 111
    Potassium phosphate 92.3
    Magnesium nitrate 69.5
    Magnesium acetate 53.4
    Magnesium sulfate 35.1
    Calcium acetate 34.7
    Magnesium citrate 20
    Calcium bicarbonate 16.6
    Potassium sulfate 11.1
    Calcium sulfate 0.255
    Calcium citrate 0.095 (25 °C)
    Magnesium carbonate 0.039
    Calcium phosphate 0.002
    Calcium carbonate (Calcite) 6.17×10−4
    Magnesium phosphate 2.588×10−4

    At least from what I can tell, the plants 'availability/uptake/dissociation' rules roughly follow the solubility rules. Makes sense when you think about it- a compound in solution that is not completely dissociated (ions are more or less stuck together, but not precipitated) makes the ions unavailable to the plant, even though they're in the solution. Of course the worst-case effect of this is precipitation and scaling, but even before then, ions can start 'locking' themselves up in solution. This is where chelators and humics come in handy- they lock up fickle cations (most Ca and Mg), but in a way that they're still available to the plants. From what I understand, the plant roots have special channels/sites that can take ions from organic acids. The roots themselves also produce organic acids in a similar way, trying to chelate cations when they're running low. This can also lead to the 'ph drop when plants are hungry' phenomena.

    pH also heavily effects solubility of phosphate and carbonate compounds- I'm pretty sure thats the main reason those pH availability charts even exist. Higher CO2 can also introduce more carbonates, making scaling problems even worse. I've been crashing the pH in my tap water (and aerating) before mixing nutes to try and gas off more of the carbonates. Even just aerating forces the water to reach equilibrium with atmospheric CO2 much quicker. I've graphed the pH and CO2 changes with fresh un-treated tap water in my system, and any down I would add would boost my CO2 levels, then as the CO2 levels dropped, pH went back up =\ So it's been much easier just doing that in advance and crashing the pH really low and conditioning it before nutes.

    And again, agree with churchhaze here- that's rather hot on the P. This last grow my levels were between about 20-30 the whole time- the way they grew.... far from 'stunted' lol. Also confirmed with phosphate test kits that the levels really never dropped that low, even though I changed my solution almost never. I just added nutes at the same mix/recipe/ratio to bump up PPMs when needed, but never added additional P past whats in the mix.
     
    Last edited: Jan 3, 2017
    churchhaze likes this.

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