#### Joshaeus

**Member**

Ammonia has a molar mass of 17 grams per mol, so we can estimate how much ammonia will be added if we know the mass of the food going into the tank, what percent of that is protein (which is listed on all fish food labels), and the tank's size. For example, I have some omega 1 pellets that are 42% protein, and I found that a ml of these pellets in a scoop is about .32 grams. To calculate how much ammonia that would add;

- Multiply .32 by how many ml of food you are adding (in this case, 1).

- Multiply the mass of food (.32 grams, per above) with the percentage that is protein (in this case, 42%, or .42). This gives us .1344 grams of protein that will eventually be converted to ammonia.

- Divide .1344 grams by the molar mass of amino acids (110 grams/mol). This reveals that we have added about .00122 mols of amino acids to the tank.

- Multiply that value by ammonia's molar mass of 17 grams per mol. This reveals that we have added .02077 grams of ammonia to the tank.

- Divide the above value by the tank's volume in milliliters (one gallon of water is about 3,780 ml) and multiply the result by 1,000,000 to find how many parts per million (ppm) of ammonia this would add to the tank. For example, if I added the above .32 grams of these omega 1 pellets to a 10 gallon, that would be .02077/37800 = .00000054947 = .54947 ppm ammonia.

So, with the possible exception of the unusual case where a fish is being underfed, we can estimate how much ammonia is going into the tank based off the food we are feeding.

This can also be extended to nitrite and nitrate; during the nitrogen cycle, ammonia is converted to nitrite (No2) and nitrate (NO3), with every mol of ammonia converted in this fashion becoming a mol of nitrite and eventually nitrate. Nitrite has a molar mass of 46 grams per mole, and nitrate 62 grams per mol, so we can estimate the amount of nitrite/nitrate we add to a tank in a similar fashion to the above, with the exception of replacing ammonia's molar mass with that of nitrite/nitrate (for the sake of argument we will assume that none of the ammonia is consumed by plants and algae prior to being converted). Doing so with the above example gives .05612 grams nitrite and .07564 grams nitrate, which - in a 10 gallon tank - is about 1.485 and 2.001 ppm nitrite and nitrate respectively.

I am hoping that (A) my research is correct, and (B) that this observation is useful for future tank endeavors, both my own and those of others on this forum. Thanks for reading