Biofloc Fact Map

Amount of biofloc and amount of bacteria depend on the ratio of Carbon to Nitrogen.
Rule of thumb: Less N = more bacteria, less floc

Ratio Carbon Nitrogen Ratio
Low 20 : 4 = 5 –> high floc, less bacteria, NH4-spikes

High 20 : 1.5 = 13 — > low floc, high bacteria, NH4-spikes – NO!

Calculating moles and grams:

Всеки хим. елемент има: Номер – Маса – Тегло


протони + неутрони
(изотоп = разл. неутрони => ако елемента има изотопи Масата = средно артитм. от всички техни Маси)

масата * разпространение в Природата

Calculating moles and grams:

Atomic mass is never an integer number for several reasons:

  • The atomic mass reported on a periodic table is the weighted average of all the naturally occuring isotopes. Being an average it would be most unlikely to be a whole number.
  • The mass of an individual atom in atomic mass units is the mass relative to carbon-12. Only carbon-12 has a mass exactly equal to itself.
  • Even the mass of a single proton (1.00727661 u), or neutron (1.00866520 u) is not a whole number. These are also the ratio of their masses to carbon-12 (since carbon-12 is the reference standard, its the only atom whose atomic mass, and mass number are the same — both are exactly
  • The mass of an atom isn’t what you’d get by adding up the masses of its individual protons, neutrons and electrons. This may seem strange, but the cause is the binding energy required to hold the atom together. This energy must come from somewhere, and is equal to E = mc2. Because energy is required to hold the nucleus together in all atoms except Hydrogen-1, a small loss of mass (the m in the equation) occurs.

Considering the possibility of confusion between the terms mass number and atomic mass, you can probably see why a lot of chemists still like to use the archaic term atomic weight instead of atomic mass.

Atomic mass (the weighted average of all naturally occurring isotopes) is not given for those atoms which have no stable isotopes. In these cases the mass number of the most stable isotope is reported, often in brackets, for example Technetium


Calculations for a 15:1 ratio of C:N using Sugar and Beef Heart Fish Food:

Sugar = 40% Carbon
=> 10 grams Sugar = 4 grams Carbon

Beef Heart Fish Food = 10% Protein
% Nitrogen in Protein = 16%
=> 10 grams Beef heart = 1 gram Protein = 0.16 grams Nitrogen

Need 15 C : 1 N:
Real weights:

A. Beef Heart:
Calculate reasonable grams of Beef Heart that will give an easy number to calculate Carbon as 15 parts:
Practical amount of Beef Heart to measure is 10 grams:
10 gram Beef Heart = 0.16 grams of Nitrogen
=> 0.16 is the “1” in the ratio 15:1
=> 0.16 * 15 = grams of Carbon needed to get the ratio 15:1 = 2.4

B. Sugar
Sugar is 40% Carbon. So how many grams Sugar to get 2.4 grams Carbon?
x * 40% = 2.4 => 6 grams Sugar * 40% = 2.4

Final weights:
6 grams Sugar (= 2.4 grams Carbon) + 10 grams Beef Heart (1 gram Protein = 0.16 grams Nitrogen)
2.4 : 0.16 = 15 : 1