1.2 mL Bacardi in a 10 gallon tank

[heyheyitsrae]

I've heard about the vodka method for saltwater tanks so I've decided to try it for freshwater. I tested my nitrates just before dosing the ethanol, I'm not sure when I'll test them again. I'll add a picture of the test tube, but I can't find my little color card to find out what the reading is. I'll try to add all relevant details, but if I miss any feel free to ask. Yes, I know that Bacardi is rum, not vodka, but from my research it's the ethanol that does the trick to lower nitrates, not whatever makes vodka different from other types of ethanol.

10 gallon tank
DIY CO2
Bubble stone on at night
Aqueon 20 filter (recently changed cartridge)
Temperature around 81
Sand/gravel substrate
pH 7.2-7.6 trying to lower it using rainwater to top up after water changes. Might as well make use of all this rain central Texas has been getting.

Mediumly planted- 7 bunches of red ludwigia, 2 stems moneywort, 4 crypts (recently prunes and separated), 2 java ferns and 5 baby java ferns, java moss. Driftwood.

Livestock- 4 scarlet badis, 1 baby guppy, 1 or 2 oto cats, 1 ghost shrimp, 5 or so red cherry shrimp, zebra nerite snail, Malaysian Trumpet Snails

It's been 5-10 minutes and nothing is dead.

 

[fort384]

I am not sure why someone would want to lower nitrates though chemical means in a planted tank? The stem plants you have need nitrogen to grow... if you are providing a proper amount of light, you really should not have any excess nitrates in that tank with your current stock. In fact, I would think at some point you would need to start dosing nitrates in the tank to keep the plants healthy, assuming you have the lighting required to keep those stems growing and happy.

It is an interesting idea, and I have seen a couple of folks try it before with limited success. The problem is there is a fine line between the amount you need to add to have an effect, and the amount that will start to cause serious problems with your livestock.

 

[Wroberson]

I'm guessing 40ppm on the color. The deck may cause the liquid to look darker I always try for a white background. Depending on the type and size of fish 40ppm can be relatively safe and NO3 is 1 of 9 marconutrient for plants.

 

[aqua_chem]

Vodka dosing has no place in FW. It is used in saltwater setups, as I understand it, not as a way of chemically controlling nitrates but as a way of biologically controlling them by augmenting denitrifying bacteria that might be carbon limited. In freshwater though, the primary source of nitrate removal isn't denitrification, but rather water changes and nitrogen uptake by plants. To my knowledge, no study or anecdotal accounts have ever showed that ethanol is a viable carbon substitute for plants, but it has been demonstrated in many occasions to be an excellent killer or livestock. You already have CO2 running, so I'm not sure what you are even trying to accomplish here.


Also, vodka is used because it is. Usually distilled well enough that is is essentially only water and ethanol. Other products are often flavored with other chemicals or still have some by products of the fermentation process. Vodka is used to remove the chance that these additional chemicals will adversely react with either the tank inhabitants or the biofilter.