my 1st sw tank was a 5 gallon with the original hob filter and regular light that came with it.wife was sick and wanted a bright fish watch on her night stand.well i put blue sand and 3 lbs of liverock in,waited 2 wks added a yellow tail damsel then a month and a peppermint shrimp,then a month and added a black n white stripe damsel and kept it for 3 yrs before getting a bigger tank.accept the shrimp,it became food for the damsels one day after molting.at one point it went 5 months with no water changes,no carbon changes,and tap water top off.if your careful about what you put in it you can run any size tank easy.just research.i take great care of my current tank and would never take chances on it like my 1st tank and yes small tanks can crash much faster like everyone says,its undenyable.but you can do it and learn alot.
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55 gallon reef with 4x54 watt t5,29 gallon sump,red monti cap,1blue echinophyllia,trumpet,red lobo,2 toadstools 1purple and 1neon,gsp,xenia and yellow xenia,red ,many mushrooms,2 giant frilly shrooms,cabbage coral,yellow polyps,many zoos,1 orange and one neon green nepthia,duncans,cladiella | 
