When people use silversides to get their eels to feed is one thing, for within silversides, they not offer much in nutrition. Like their are good for using to get your eels to feed and once feeding begins, move to feeding small strips of fresh fish and other varieties of foods. And RMPD109, like the location you posted, they say a 50 gal
tank do well and others a 55. The thing is the SF can grow even larger then two feet and you could be surprise to how large and with that, no smaller a tank then a 65 and as large if one can a 75 or better and before i forget, you find that many would tell you that a SF grows 3', but still can grow a bit larger.
Like people would tell you all that an H. Dragon Moray grows 2' and a number go with 2.5' , and yet my male dragon appears to be the size of 34" and the female is a bit smaller, about 31-32"
There is always some misguidance information out on the net and one needs to look more around and not be fooled by the first thing they read.