Hello out there...I'm no expert in the aquarium keeping hobby and don't know too much as far as quality of the various products out there. I've recently set up a 55 Gal tank and have everything I need for it but a heater. I've looked up some name brands and was thinking about purchasing a Hagen...anyone out there know if they're any good? Or if there is a brand that would be better? I've been recommended a Hagen Thermal but I would like to hear more options/opinions before I decide. A few of the fish (including my black ghost knife) in my tank would probably really appreciate a higher temperature for their well-being. Oh, this brings me to another question (might as well as at the same time)...about the black ghost knifefish...how fragile are these guys when they're young (size being about 5 cm tops)? I've been reading up on them but all the information I seem to find pertains to larger sized one's that probably aren't as sensitive. Either that or the information I've encountered has left me more confused because the facts are so diverse. Really appreciate it. Thanks all.