Relationship between carbon source and alkaline

[Jack.lin92]

Hello Dear randy
Why is it recommended when using carbon source that alkaline has to be between 7 and 8 ?
Thank you

 

[Cory]

I believe because of low nutrients. Since there will be less no3 and po4 in the water because bacteria consums it, a dkh of 7 slows the fleshy growth part thus less no3/po4 demand on the coral.