Cheato is a type of algae that grows in filaments as opposed to being leafy. Picture string all bunched together. It grows pretty quickly, taking nutrients out of the water and binding them into growth. You then remove the nutrients from the system by pruning some of it out periodically. Another benefit is that pods (small crustaceans that many fish eat) tend to reproduce well in it.
Should you use it? That depends, but many people like to.
Oh, we generally break algae into two types-microalgae, the stuff that is too small to see easily, and macro algae, which is bigger.
Also Cheato is short name. Full name is.
Chaetomorpha Algae, also known as Spaghetti Algae, is an excellent macro algae for refugiums. Each cell grows end to end, creating long, stiff strands. It grows in filamentous clumps, resembling a ball of fishing line.
Not sure where your located. I suggest finding a fellow reefer locally and get it from them. If you lived in MA or NH we share it locally when others start refugium. If you have it you throw away bunches. Thats how the nutrient export works.
I just got some Chaeto yesterday . . For the first time.
I went to a LFS and asked for $5 worth. I got a tennis ball size lump.
In my growing paranoia on safety and hitchhikers I dipped it in some RODI for a minute.
We'll see how that goes. . . .