# Input data for Algae

I want to do simulations on algae.The only information I know about algae is that the Cyano.:Green:Diatom ratio is about 2:3:5, and total Chl-a.If carbon-to-chl-a ratio for cyano.(CChlc) is 0.06 and total Chl-a is 40ug/L,is the input value for cyano. calculated as follows?40x0.2x0.06 = 0.48 mg/LAnd if there is any literature related to this, please let me know

Hi Seok,
Letâ€™s convert the unit of these quantities first:

• CChlc = 0.06 (gC/mgChl) = 60 (mgC/mgChl)
• Total Chl-a = 40 (ug/L ) = 0.04 (mg/L)
For algae x, chlorophyll a can be converted to algae biomass concentration using: Bx = CChlx* Chl-a
in which: - Bx is biomass concentration of algae x (mgC/L)
- CChlx is carbon-to-chl-a ratio (mgC/mg Chl)
- Chl-a is chlorophyll a concentration (mg Chl)
Now suppose the biomass concentration of Cyano, Green and Diatom is: 2y,3y, 5y respectively. The total chlorophyll a from 3 algae groups can be calculated as:
Total_Chl-a = Bc/CChlc + Bg/CChlg + Bd/CChld = 2y/CChlc + 3y/CChlg + 5y/CChld
So, to calculate the cyano concentration Bc, in general you also need to provide CChlg and CChld.

However, with EFDC, we suggest to use the same value of carbon-to-chl-a ratio for all three algae, so you can have:
Total_Chl-a = 10y/CChlc
Hence, the cyano biomass concentration is: Bc = 2y = 0.2 x Total_Chl-a x CChlc = 0.2 x 0.04 x 60 = 0.48 (mgC/L)

The value you obtained is correct but just the unit. I hope this answers your question.

Kien