A snowflake eel can get to about 24" in captivity. I don't think a 29-gallon aquarium is big enough. I pulled the quick stats on Snowflake's from Live Aquaria.
http://javascript:popupWindow('/product/refinement_definition.cfm?rid=1', 50, 50, 450, 400, 'scrollbars')">[B]Minimum Tank Size[/B]</a>: 50 gallons [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=2', 50, 50, 450, 400, 'scrollbars')">[B]Care Level[/B]</a>: Easy [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=3', 50, 50, 450, 400, 'scrollbars')">[B]Temperament[/B]</a>: Semi-aggressive [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=4', 50, 50, 450, 400, 'scrollbars')">[B]Reef Compatible[/B]</a>: With Caution [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=8', 50, 50, 450, 400, 'scrollbars')">[B]Water Conditions[/B]</a>: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025 [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=10', 50, 50, 450, 400, 'scrollbars')">[B]Max. Size[/B]</a>: 2' [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=11', 50, 50, 450, 400, 'scrollbars')">[B]Color Form[/B]</a>: Black, Tan, White [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=13', 50, 50, 450, 400, 'scrollbars')">[B]Diet[/B]</a>: Carnivore [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=15', 50, 50, 450, 400, 'scrollbars')">[B]Compatibility[/B]</a>: View [IMG]http://www.liveaquaria.com/general/compatibility_chart.cfm">Chart</a> [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=16', 50, 50, 450, 400, 'scrollbars')">[B]Origin[/B]</a>: Indo-Pacific, Vanuatu [IMG]http://javascript:popupWindow('/product/refinement_definition.cfm?rid=17', 50, 50, 450, 400, 'scrollbars')">[B]Family[/B]</a>: Muraenidae
Hope that helps.