To be completely honest, this has got to be the worst fish I have ever kept. Not only are they inefficient algae eaters, compared to some, when they mature they start to feed off the slime coat of their tank mates. This I found out the hard way.
I found one 8 inch SAE that had trapped a 15 inch long finned goldfish behind a rock...all I could see was part of the goldfish's tail and frantic movement...I moved the rock thinking the goldfish had got itself trapped, only to find a very still and submissive goldfish with many, many scales missing and all of his beautiful fins ragged... and a very arrogant looking SAE evacuating the area. I isolated the goldfish to treat him, and almost immediately the SAE started on a 12 inch shubunkin. He was an absolute terror! The first goldfish (a well loved 8 year old) was dead within 48 hours, despite my efforts. Note, this incident happened in the space of two hours from when my hubby left for work and I arrived home from work.
I decided then to isolate him, and they are a nightmare to catch ...I had to empty the tank of *everything* to get him out...the stress of the capture killed him within the week.
That said, for the previous three years he looked cute, and appeared fairly shy. I think the balance was tipped when I removed a couple of older fish to a pond, then he just suddenly went nuts.
I won't be keeping one of those again. BTW, he was not my first, I had four previously (on different occasions) one died the day I bought him, another got lost permanently underneath an under gravel filter (?) and two died from the stress of
relocation. I used to love them, until i had one grow to maturity...
Just my opinion. I wish you the best of luck!
This might seem an extreme tale, but I doubt he is an exception to the rule.