How to find the concentration of fertilizer AFTER it's been mixed with water?

[Clint]

I think I'm going to give Terracycle another shot. I stopped using it because I thought it was rip off when it comes to price, but now I'm going to play with it again since I'm downsizing anyway and it has less crap in it than what I already use. Maybe it won't burn one of my plants, is what I'm hoping.


It's sold pre-mixed, so the NPK concentration is .02 .002 .02. I'm not used to working with these numbers lol. I'd like to compare it to other fertilizers, like Maxsea 16 16 16, Schultz orchid food 19 31 17, Neptunes Harvest 2 3 1 and Alaska Fish Emulsion 5 1 1 AFTER they have been added to the amount of water listed in the directions on the back of their containers. They have a version with extra N, but their website doesn't list the concentration. If I squint I think I can make out .25 instead of .2.

By the way, if you ever want to buy it, read the labels. The orchid, cactus, general, tomato, violet, and herb formulas are all exactly the same, they just have different labels Kind of hypocritical when they could print one label and save energy and resources... I mean that's sort of what the company is about...

 

[Pyro]

C1V1=C2V2

You know C1, V1 and V2 so solve for C2

 

[Clint]

Take maxsea for example. Looked it up and it says to use one tsp per gallon, and the concentration of TC will be .02 per gallon, so I keep getting .02 for an answer. I'm doing something wrong Am I over complicating things and the concentrations are just divided by ten when the directions say to add one tsp. per gallon, divided by five when it says two, etc. ? If that's the case then the fish poop's concentration is .05 . 01 . 01 for example.

Terracycle's looking pretty weak right about now

 

[Pyro]

Well if the total concentration after dilution is given then you need not run the equation... Or am I missing something??

If you know your starting concentration then you should be able to figure the final concentration but it sounds like you do not know the starting concentration, just the end concentration if you do a 1 tsp/gallon. So run it in reverse first.

(C1)(1tsp) = (0.02)(768tsp)

Solve for C1 = 15.36

Now run it the other way

(15.36)(1tsp) = (C2)([Xgallons]*[768])

So if you are making it 10x dilute then you are basically making a 1tsp in 10 gallons so it would be:

(15.36)(1tsp) = (C2)(7680)

Which becomes:

15.36/7680

or

0.002