Hi, I am hoping someone here can give me some info on the best exact chemicals and amounts to use in the mid flowering stage. I had some pest problems last year and the folks here were very helpful!
All I can find is a few conflicting NPK ratios and a lot of ads for ready mix fertilisers, but nothing solid on the amounts or ratios of the chemicals used, including trace elements and others besides NPK.
I am growing in an outdoor soil/hydroponics hybrid system that works very well. We top feed pots of soil set into a hydro tray of perlite and mix all our own chemicals from scratch for the big water drum.
We are about 3+ weeks into flowering and I am beginning to see nutrient burn. What I would like to find out is the best mix of chemicals for this stage. We have a good supply of individual chemicals I just need to know which ones in what amounts are best for flowering outside in the sun.
In the interim I have flushed the system with plain water until I can discover the best mix of nutrients. I understand there are a lot of good ready made fertilisers out there, but I was really wanting to know specifics such as chemical compounds and amounts of each. Thanks
Thank you very much for the information, this is very helpful! Are these now the correct ratios for the flowering stage?
My plants are from Bergman’s seeds and I think we are using Bergman’s recommended nutrient balance for the growth stage. It appears to be a bit too strong for flowering however. I’lll find my current formula and post that too.
I’m keeping the garden fairly well dowsed with pyrethrum for pest control and hoping to go at least another 5 weeks, with the last week or so back to plain water to flush it all out. So far so good, other than a few wee burnt leaf tips.
A list of what you have would be a great start. I believe you said you had the chemicals. I just need to know what you have.
You said " and mix all our own chemicals from scratch for the big water drum. " and " . We have a good supply of individual chemicals I just need to know which ones in what amounts are best for flowering outside in the sun."
Here is the breakdown of what I am using now. The pH is between 5.5 and 6.5. The supply is from a 200L drum:
Nutr. mg/L(ppm) total g/200L
--------------------------------------------
N 196 39.2
P 31 6.2
K 279 55.8
S 333 66.6
Ca 160 32
Mg 75 15
Mn 1 0.2
Fe 5 1
Cu 0.2 0.04
Zn 0.2 0.04
B 1 0.2
Mo 0.1 0.02
The nutrients are sourced as follows:
N urea
P solid diammonium phosphate
K potassium sulphate (K2SO4)
S from the other sources, no shortage
Ca calcium chloride
Mg epsom salts magnesium sulfate (MgSO4)
Mn from Manutec (brand) Mn Zn
Cu copper sulphate
Fe iron chelate
Zn from Manutec (brand) Mn Zn
B as borax
Mo ammonium molybdate
There are also of course trace minerals such as copper in the soil, which is I think one of the advantages of our hybrid soil/hydroponics system. This is large pots of soil watered from the top (with valve) which drain into a large hydro tray of perlite and back into a 200 L drum. The watering occurs every 2 hours on a timer.
I don’t think the problem is bad enough to submit a ticket and as I mentioned I emptied the tank and went back with plain water for now. I had a few leaves yellowing and several with brown leaf tips from the edges which looked like classic nutrient burn.
Actually no. This is the second year using this method and both times the plants have grown beautifully. Last year’s crop was a Humboldt seed strain and did not have the nutrient problem, although it did have a pest problem that I was able to manage until harvest.
@GrowGirl,
Be careful testing your measurements with using EC as some salts have higher EC then others, when comparing by mass or volume. EC is a measurement of electrical conductivity, and not an actual measurement of ppm, and is much more suited for measuring overall strength of nutrients in mixes, and not individual nutrients. I fear your readings are off. I use a combination of different colourimeters and spectrometers, along with simply colour test kits, to read actual ppms and ppbs.
Thank you for the tip Dumme I know that urea has no conductivity but still has solid parts, but yes, the EC metre is what we are using just to test the overall strength of the entire mix, not the individual nutrients. That measurement comes strictly from keeping track of what amounts we have added over time.
For now I am thinking to try the 3-10-10 mix as recommended in the link I quoted. I have some really nice buds developing so If I can just keep everything growing a few more weeks I’ll be happy!
