there are a number of things you can do if you have alot of plugs. 1.you can fins a gfci strip. this will have about 6 outlets on it so you can just plug it in the old outlet.
2. you can replace all the outlets in a 6 foot radius of the tank
3.buy a gfci circut braker for all the outlets in that room
the third option is very expensive but it will cover you totally. i dont rcomend you do this one if you never have done electical work. its simple but you can really mess up your breaker box if you mess up, or you can get eletricuted. i would recomend an electrition for the third option