Just an FYI, the tire track eel can get up to 37-40". It is possible that it will only get to around 24" and stop but many have them larger.
Also, at that size, they will probably need something more substantial than frozen bloodworms. Some people have talked about their fire eels and tire track eels (they are pretty close to the same eel) eating a dozen large night crawlers at once.
I'm glad I am having success in getting mine to eat the red wigglers because they are so healthy and have a lot of protein.