A question of liquid ferts

Trying to understand NPK numbers. I have a 5-5-5 liquid fertilizer that is supposed to be mixed with 10L of water. If I doubled it to 20L would that make it 2.5-2.5-2.5, or is that not how it works?
 
filmost said:
Trying to understand NPK numbers. I have a 5-5-5 liquid fertilizer that is supposed to be mixed with 10L of water. If I doubled it to 20L would that make it 2.5-2.5-2.5, or is that not how it works?
When you mix the volume specified for 10 L into 20 L then the result is a half strength fertiliser solution. If you took 10 mL of the concentrate and diluted it with 10 mL of water then you would have 2.5:2.5:2.5. Thus it follows that diluting a small vial of liquid fertiliser into 20,000 mL would not result in a solution with an NPK of 2.5:2.5:2.5.

A cursory web search yielded a page covering Solution Concentration Calculations on faculty.css.edu.
 
So you're saying if did 1 part concentrate + 1 part water, then I would be halving the NPK ratios? Which follows that 1 part concentrate + 2 parts water = 1.6-1.6-1.6?
 
Then when it comes time to use it, I would further dilute it based on say the original instructions of 1 cap / 10L of water? I assume this would be how it works because even with store bough 1-2-1 or 2-1-1 ferts, you would still dilute it before use right?
 
Andy21 said:
Why not just make 10l at a time? :) lol
 
No where to store it! During the actual growing season when they are outside I can make 10L and use it all up, but during the seedling stage indoor it would just be a waste!
 
And on that note, when would you usually start fertilising seedlings?
 
Hey mate, yeah I understand now lol with my seedlings I usually start giving them a really low dose when they get there second/third set of leaves, usually about 1/3 strength liquid seaweed solution, it's a product called Seasol it's pretty basic, I wait til they're bigger before I start giving them different ferts, everyone does things differently though, usually trial and error is the best way to find out what works best for you and your growing conditions
 
Haha I see, well guess I will continue to wait then. And in the mean time will try to track down some seaweed solution. It's odd but I can't seem to find that stuff anywhere (I'm in Japan), same with fish emulsion.
 
I saw this post and had to create an account and chime in. From my understanding, I've been growing hydro for some time now, that no matter what your concentrate will always be 5-5-5. 5% Nitrogen, 5% Phosphorus, and 5% Potassium, changing the nutrient concentration comes with how much you dilute it. Lets say a liquid fert says to use 10mL for 1gal, even if you put in 5mL you would still be adding a concentrate of 5-5-5, but if you used 5mL for one gallon the nutrients would be at half strength.  A way to test your nutrient concentration is by getting a ppm/TDS/EC meter, and I highly recommend one to monitor the exact levels your giving your plants. 
 
As for how much to feed your plants it depends on how big they are
~100ppm for sprouts 
~early veg 300-400ppm (usually 1/4 of what bottle says) 
~late veg 450-700ppm
~early bloom 750-950ppm
-full bloom 1000-1200ppm 
 
Depending on what you have for a nutrient they may have a nutrient calculator on their website. The use and ease with a ppm meter is really nice, being able to know how much your actually feeding your plant, esp when you start using 2, 3, or more different bottles. 
 
Though for soil I second Proud Marine Dad, mix a killer soil and I usually only end up adding molasses 
 
Thanks guys! Yeah this is just for my starts and what ever I keep in a container. The rest of the plants will be going the ground come spring.

This will be our second year (new house) so I am still working on the soil which was a newly added Red dirty when we moved in. I mixed in a bunch of bark compost last year. This year will be adding leaves and worm compost. Do you have any tips for other things to add?
 
Proud Marine Dad said:
Why not make a good, healthy soil from the start and you won't need to fertilize at all during the entire growing season. :)
This is what i do.  When mine get bigger i feed them organic nutes.  When they go outside i feed them tea i brew.
 
This is what i do.  When mine get bigger i feed them organic nutes.  When they go outside i feed them tea i brew.


Is that all you feed them outside? Do you have a specific recipe you use?
 
filmost said:
Do you have a specific recipe you use?
 
I get by with just watering with teas in my garden and potted plants. Although mixing a killer soil is key for having healthy happy plants, and taking care of your microherd making sure not to kill them with synthetic ferts. 
 
People usually use different recipes. There is a thread http://thehotpepper.com/topic/32001-beginners-guide-to-aactcompost-tea/ that details the process. 
 
My base recipe is-- 
5 gallon batches, and I use my girlfriend's pantyhose leg/foot to hold everything I add in (or a sock)
 
2 Handfulls Ancient forrest (Alaskan humus)
1 Handfull Earthworm Castings 
1/2 scoop Great White (mycorrhizal inoculant)
2 Teaspoons OG Veganic special sauce (mycorrhizal inoculant)
1 Tablespoon liquid kelp
1 Teaspoon humic acid
1 Teaspoon Fulvic acid
1 Tablespoon unsulphured molasses (or blackstrap)
-this is also great for running a live hydroponics setup, keeps pythium away like a charm
 
Then depending on how old/what stage the plant is in I add in guanos with appropriate NPK ratios. They usually don't even need the guanos since the soil is quite rich. I'll use them to give a little boost when the pods really start coming and I notice a plant could use some help.
 
Keep it simple! All these ingredients are just something people think they need because the Canna growing hydro people told them they need them. :rolleyes:
 
filmost said:
 
What do these two acids do?
 
Proud Marine Dad said:
Keep it simple! All these ingredients are just something people think they need because the Canna growing hydro people told them they need them. :rolleyes:
 
Keeping it simple is highly recommended yes, but in my case I've gotten many freebies over time, including my humic and fulvic acids. You do not by any means "need" the items in my recipe it's simply what I use. Don't go out and buy everything you see in someones recipe get the bare minimum to start. And as ProudMarine Dad said, don't listen to what a guy in a store tells ya, they are trying to make they're buck.
 
Info on humic and fulvic acids - Humic acid is produced by biodegradation of organic matter, it is not one single acid, it is a solution of many. Fulvic acids are essentially the same as humic but they contain a higher oxygen content, and can pass through membranes easier since they have a lower molecular weight. (more indepth on humics http://www.thesoilguy.com/SG/HumicAcid )
 
If you use Humus (ancient forrest/denali gold or any other brand) in your tea you will get your humics and fulvics from that. I add a little extra in my case because I have found that when running same plants side by side treating with humic and fulvic and with out. I observed healthier roots in the humic/fulvic group than in the control (lacking additional humics/fulvics) this was in a deep water culture so there would be no naturally occurring humics/fulvics, but since I saw that I was sold on the use of them and when my samples run dry I will most likely purchase more. I'm not sure if this would greatly benefit soil as I ran no tests in soil plants. However, it is clearly not hurting mine. 
 
Alright all. I picked up a 3-3-2 organic liquid fertilizer. Dunno what it is made of, only that it is 100% organic. Do you think I can use this at full strength or should I halve or even quarter it?
 
This is of course only for my starts. Once the weather warms up I will be amending compost to my soil and planting out.
 
filmost said:
Alright all. I picked up a 3-3-2 organic liquid fertilizer. Dunno what it is made of, only that it is 100% organic. Do you think I can use this at full strength or should I halve or even quarter it?
 
This is of course only for my starts. Once the weather warms up I will be amending compost to my soil and planting out.
It's impossible to know what strength you should use given the complete lack of information on the composition. In past seasons I had to drop one fertiliser down all the way to 1/8 strength to allow more regular use. I don't remember the last time I used any of the liquid concentrate or soluble NPK fertilisers at full strength.
 
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