skip to main content

Container Gardening

Fertilizer math help needed

6 years ago

I've been kicking around the idea to make my own liquid fertilizers out of the dry ingredients from my aquarium fertilizer from NilocG Aquatics. I have Potassium Nitrate (KNO3; 13-0-44), Monopotassium Phosphate (KH2PO4;

0-52-34), Potassium Sulphate (K2SO4; 0-0-50) and CSM+B (minors) but am struggling with how to translate the recipie I have for the aquarium to terrestrial plants. Does anyone do this or have any insight, or be able to point out a website that can explain this?

Sort by:Oldest

Comments (9)

Travis (Central WI 4a-5b)
6 years ago
If they're dry fertilizers they're just percentages. I would think you could just figure out how many lbs would dissolve per gallon. For example if you could dissolve 10 lbs of KNO3 in a gallon u should have 1.3 lbs of N and 4.4 lbs of K2O. I'm not sure on solubility or anything like that of these. If you want to create your own custom analysis I would blend the dry first then dissolve it. I can help you more with that if you need. I've done it for commercial agriculture before with fertilizers. What analysis are you trying to achieve?

Travis
Nil13 usda:10a sunset:21 LA,CA (Mount Wash.)
6 years ago
You're never going to be able to make a vegetative fert with what you have. You're going to need to add N. You want a basic ratio of 3-1-2 or 3-1-3. You'll need urea at 46-0-0.
Related Discussions
Help with fertilizer math
Q
Comments (11)
OK, Al, this is scary, because I think I understood you! I was poking around with a spreadsheet after your 15:55 post, and I actually came up with a 6.9:1:3.8 ratio for ACTUAL P,K for the 3:1:2 "as sold" ratio. Not far off of your number above! I had to dig deep into the recesses of my memory for terms like moles, molecular weight, etc. At the risk of continuing to monopolize this thread, but on a related topic, the reason that I have such an interest in this is that I wanted to take a 1.5 pound box of MG 24:8:16 with minors and make a concentrated solution, then use the more accurate measurement of liquid measurement over granular. I find that as the season progresses, my fertilizer becomes clumpy and less accurate to measure. My target is to dilute to approx 300 ppm N for fertilizing. If I take the whole box and mix to make 2 liters, I could then use 2 teaspoons of concentrate per gallon and achieve 304 ppm. This is assuming 2000 mL of water, which would likely be less when actually measuring. Of course I would measure the actual amount of water, and this would then drive up my concentration, forcing me to reduce the 2 teaspoons. (If the actual water portion is 1500 mL, then the 2 teaspoon/1 gallon example would be driven up to 499 ppm) I have been wanting to try this for years, but never sat down to work out the numbers until today, which is why the interest in this thread. Thank you for indulging my obsession! Barb
...See More
Hydro fanatic///not math need help???
Q
Comments (2)
A cubic yard contains 3x3x3= 27 cubic feet. A 3 gallon pail will hold about 1/3 cubic foot. So, 100 pails X 1/3 cubic feet = about 33 cubic feet, or a bit more than a cubic yard. Most companies will not deliliver that small amount. Probably, you could carry about 1/2 yard in a pickup truck. So, two loads ought to do it. I think I paid around $30 bucks per pickup load some years ago. It's probably changed by now. I would suggest that you try a 1/2 dozen of the small pails first. For a tomato, there might be too little room for the roots in a pail that small. Maybe someone else may have more information for you. I talked to a fellow who said they grew their hydroponic tomatoes in sawdust with real good results. I think they used gunney bags for the containers. chuck
...See More
Need help with math for a recipe
Q
Comments (3)
I'm ready to help, but I have some questions...do you have the recipe (if not, I do). How many batches (or squares) do you want to make? Have you made these before (if not, I have tips for you...). Also, they only stay fresh for a day or two, otherwise they get kinda hard. They are easy to do, so you could do a test run and then make the real ones just before your Easter fun. I'll check back later today.
...See More
Need help with math for a recipe
Q
Comments (19)
Cereal is sold by weight, not volume. Most manufacturers state that the product settles, so do not give an exact volume. To find out, measure. Take one box, open it, and begin filling a measuring cup and dumping into a bowl. Count the number of cups until the box is empty, and then you will know how many cups were in one box. Marshmellows: 15 serviings of 2/3 cups per bag. 15 x 2/3 = 10 cups per bag Again, you could simply measure. But, appearently, what you wanted to know is how much to buy when you go to the store? For cereal, I recommend measuring one box to find out because the stuff settles and is sold by weight, not volume. The other trick is that sugared cereals weigh coniderable more than un-sugared. Check the weight of the contents and divide into the price per box. This gives you the price per oz or lb. Now, check the price of sugar and I'll bet that the price per wight of cereal is much more than sugar! The cereal makers are selling you sugar at high prices, and have been doing so for many years. What's more, the price of sugared cereal may be greater than the unsugared. The cereal companies make more profit on sugared cereals than for plain cereal because they are selling sugar at above the average price for sugar.
...See More
Nil13 usda:10a sunset:21 LA,CA (Mount Wash.)
6 years ago
Hydrobuddy should be helpful. http://scienceinhydroponics.com/2016/03/the-first-free-hydroponic-nutrient-calculator-program-o.html
mblan13
Original Author
6 years ago
Trying to formulate a low N fertilizer. I went to a hydroponics shop and got a 2 part fertilizer for growing/flowering.

The fish generally take care of the N in the Aquarium! Espoma sells blood meal (12-0-0) and urea (45-0-0)

Thanks for the HydroBuddy link. That should get me where I need to go.
Nil13 usda:10a sunset:21 LA,CA (Mount Wash.)
6 years ago
You really don't want to use blood meal.
mblan13
Original Author
6 years ago
last modified: 6 years ago
Why not? I wonder if I could get 100% bunny blood meal...bunny bone meal too. That would make them think twice about eating MY plants! ;D
FastInk
6 years ago
Cross reference your ferts between a known water soluble fertilzer like MG and use the dosage recommendation of that. Divide that recommended dosage by 2 and start there. Rough estimate, about a tablespoon per gallon. You'd mainly just want to use the one that has Nitrogen in it.
Nil13 usda:10a sunset:21 LA,CA (Mount Wash.)
6 years ago
Blood meal is nasty and doesn't dissolve well. It's better as a top dressing for in ground plantings as long as you are ok with your garden smelling like rotting corpses.
mblan13
Original Author
6 years ago
Thanks Fastlink & Nil13. Rotting corpses, eh? Nah...might attract zombies!

Related Stories

GARDENING GUIDES Get on a Composting Kick (Hello, Free Fertilizer!)

By Matt Kilburn

Quit shelling out for pricey substitutes that aren’t even as good. Here’s how to give your soil the best while lightening your trash load

Ideabook 911: I Need Help Staging for Resale

By Becky Harris

GARDENING GUIDES How to Feed Your Plants for a Healthier Garden

By Noelle Johnson Landscape Consulting

Here’s what you need to know to choose a fertilizer that best fits your plants’ needs

GARDENING GUIDES How to Keep Your Citrus Trees Well Fed and Healthy

By Noelle Johnson Landscape Consulting

Ripe for some citrus fertilizer know-how? This mini guide will help your lemon, orange and grapefruit trees flourish

COLOR How Color Can Help You Stay Organized

By Laura Gaskill

This simple trick goes a long way toward helping everyone in the household quickly find stuff — no labels required

PETS 6 Ways to Help Your Dog and Landscape Play Nicely Together

By Marianne Lipanovich

Keep your prized plantings intact and your dog happy too, with this wisdom from an expert gardener and dog guardian

COLOR Pick-a-Paint Help: How to Create a Whole-House Color Palette

By Laura Gaskill

Don't be daunted. With these strategies, building a cohesive palette for your entire home is less difficult than it seems

LANDSCAPE DESIGN Native Plants Help You Find Your Garden Style

By Oakley Gardens

Imagine the garden of your dreams designed with plants indigenous to your region

CONTRACTOR TIPS Contractor Tips: 10 Home Areas That Likely Need a Pro

By Buckminster Green LLC

Safety, less cost and better aesthetics on a home improvement project may rest in the hands of an expert

FURNITURE How to Buy a Quality Sofa That Will Last

Learn about foam versus feathers, seat depth, springs, fabric and more for a couch that will work for years to come

Sponsored

More Discussions

Firefly Petunia in Containers Outside

4

Yellow leaves: to remove or not?

5

was just gifted a starter gardenia bonsai

1

How to prune dracaena

0

Water plants exposed to the sun

1