When the water quality changes suddenly, the grape algae may whiten in a large area, which is almost irreversible. For some fish such as upside down, grape algae is a good snack. If you want to keep grape algae in the fish tank, you can't keep these fish.

In fact, sea grape is a kind of grape algae, which is sold in coastal towns in Southeast Asia. Generally, it can be eaten cold, which is said to have the effect of clearing away heat and toxic materials.