Mixing food with vinegar

UK_Pete · Feb 18, 2015

Hi Randy,

For simplicity I was thinking about mixing blended fish food (clams, fish, squid etc) with vinegar so I can feed and dose at the same time (maybe it would even preserve the food so it didnt need to be refrigerated I thought). But then I remembered that some fish is sold in vinegar and it goes white and I assume denatured. Do you think that it would change the nutritional value of the food if I did this, and would using something like calcium acetate instead mean the fish would remain unmodified by the acid?

Thanks, Pete

Randy Holmes-Farley · Feb 18, 2015

It might taste pickled to the fish and they might not eat it. I'm more sure on nutritional value. Some vitamins may not be stable for long at that pH.

UK_Pete · Feb 19, 2015

Thanks Randy. Could you give an opinion about sodium acetate instead of vinegar?

Randy Holmes-Farley · Feb 19, 2015

Sodium acetate won't impact food nutrition and likely not palatability by fish either.

UK_Pete · Feb 19, 2015

Great thanks Randy. I think I'll make some sodium acetate with lye and vinegar, evaporate some of the water off and use it to make frozen liquidized cubes then, as I am trying to increase the organic nutrients in my tank ATM. Results so far from feeding food and vinegar heavily are positive looking effects on corals

Randy Holmes-Farley · Feb 19, 2015

Remember that it will also boost alkalinity.

UK_Pete · Feb 20, 2015

Oh didnt realise, guess I can see how though. So maybe something like ethyl acetate would not add alk or interfere with food quality? Since ethyl acetate is C₄H₈O₂ and vinegar is C₂H₄O₂,to work out the equivalent, would you base the weight on what proportion the of molecules weight is carbon? So ethyl acetate is 55% carbon, acetic acid is 40% carbon, does that make the ethyl acetate 55/40 = 1.375 times more effective by weight or does the amount of oxygen in the molecule come into play too? I'm wondering if the greater proportion of oxygen in the acetic acid form means the carbon is already 'partially oxidised' so to speak and so provides less potential for oxidisation and hence energy.

Interestingly ethyl acetate would be the cheapest source of carbon here:

Price per kg acetate / ethanol:
vodka = $81 (almost all tax),
vinegar = $56,
99% acetic acid $15,
Ethyl acetate = $12

Randy Holmes-Farley · Feb 20, 2015

The utility to organisms is more complicated than % C. CO2 is useless in this regard, for example, but still has carbon. Ethyl acetate could be fine, but in a concentrated mixture won't dissolve fully in water, but would be OK to dose.

Maybe just ethanol for this idea?

UK_Pete · Feb 21, 2015

Thanks Randy, I did wonder about the food value of molecules that have the same number of atoms but in a different arrangement. Totally see what you mean about ethanol too - it would have quite a few benefits. Only thing is AFAIK it dosent freeze, I have a friend who keeps vodka in the freezer and it has a strange very high viscosity while at -18 C but does not go solid. In a way it would be far better, because I guess it would be an excellent preservative, so I could keep the food mix at room temp, and just use a large bore peristaltic pump to dose it, which would be really great. I really did want to move to vinegar partially just to see how it affects things, but guess it might be not compatible with this idea as you say.

One slight issue is that non denatured ethanol is priced extremely high in the UK, but I can get isopropyl for less than a tenth the price. Since the isopropyl molecule is quite similar to the ethanol is it possible to say if its as biodegradable and suitable for bacterial food? Would methanol be a better alcohol (because of its toxicity it would be a second choice if the option to use isopropyl was there). Or any other alcohols or other substances that might both preserve and act as a carbon source?

Thanks, Pete