Diluted things go off.

Certain things act as preservative: sugar and salt for example. If you dilute orange juice, it will go off. It should be drunk at the time of dilution.

Maybe it doesn't matter if diluted fish emulsion goes off. I don't know. I rarely use liquid fertilizer and when I do, I use it immediately after dilution.

The high concentration of minerals (salts, ions, etc) in the concentrate is a preservative.

When you dilute it, the anti-bacterial effect id gone, bacteria will start to grow and metabolize the dilution. It will REEK! And some of the nutritional value will be lost. But mostly is will just stink.

Why would you not follow label directions? There are many things that should not be diluted and stored.....some fertilizers, herbicides, fungicides, and insecticides are the common gardening products.

Some sources indicate that these liquid fish fertilizers have small quantities of preservatives (phosphoric acid is one) added which would be ineffective in the normally diluted mix which would allow disease pathogens to then live and grow in that diluted mix. In some instances storing diluted fertilizers, herbicides, fungicides, and insecticides will simply clog up the spraying equipment and is the majot reason most manufacturers will sway to empty and thoroughly clean that equipment after each use.

kimmq is kimmsr

Most of those pesticides begin to lose their effectiveness as soon as they are mixed with water....that's the most important reason for making only what you are going to use at any one time.

Rhizo, why I wouldn’t necessarily
follow the mfg’s directions is a fair question. For one thing, I’d overlooked the warning, so had been doing
it contrary to those directions, storing for a limited time, without apparent
problems, emphasis on “apparent.” And, too, I’m happier to follow a general
direction like this when I know why I'm doing it; as much as anything it was a matter of curiosity.

I appreciate all the responses here. Kimmq's reference to phosphoric acid (which would adjust the pH) was on point, I think. In any case, let me add the response I received from
Neptune’s Harvest, which may be of interest to those following this thread:

***We stabilize the Fish to a pH of
3.5 to keep it from rotting and going bad. Once you add water the pH goes up,
and if you don’t use it right up it will be begin to rot. It will work fine,
but it will stink to high heaven.

I like to put it this way. How long
would you leave a piece of fish on your kitchen table before cooking it? That
is the same amount of time you can leave the Fish diluted, without stinking you
out.***

My takeaway: Stored diluted emulsion will work fine, but will in
short order begin to stink. Also, products sold as pre-diluted will presumably have their pH adjusted accordingly.

Gary

Ammonium that is quickly and readily used by plants smelled so bad. Smelling bad does not make a fertilizer less useful.

Any actual scientific facts to support the responses here? I too have a curious mind....

As an environmental chemist I concur with the conclusion that diluting fish emulsion will allow microbes to grow, which can 1) smell bad, 2) waste nutrients such as nitrogen through offgassing, 3) possibly grow microbes that are pathogenic to either plants or humans, and/or 4) clog up your sprayer.