Aside from having zero of either Po4 and N03 it comes down the visual observation.
If the corals shutdown---small polyp extension and dry look over most corals you need more fish. You're looking for this over most of the corals.
The other part is drab coloration and no growth.....growth= color. You can have corals with good polyp extension just no growth and color.
Usually your glass panes are also a good indicator......you should be having to clean the glass of film every few days.
Just having enough fish isn't the whole equation. You have to feed them well so they look filled out with good colors. So in this respect ,the fish themselves can help provide more visual ques.
The whole idea is the have high throughput but not so much left over to get such high test numbers that the excess nutrients let algae get out of control or to stump coral growth.
If the corals shutdown---small polyp extension and dry look over most corals you need more fish. You're looking for this over most of the corals.
The other part is drab coloration and no growth.....growth= color. You can have corals with good polyp extension just no growth and color.
Usually your glass panes are also a good indicator......you should be having to clean the glass of film every few days.
Just having enough fish isn't the whole equation. You have to feed them well so they look filled out with good colors. So in this respect ,the fish themselves can help provide more visual ques.
The whole idea is the have high throughput but not so much left over to get such high test numbers that the excess nutrients let algae get out of control or to stump coral growth.