What to look for?

[Ikan Besar]

replacing the tank in an 18' isn't all that big a deal really: remove the console which is screwed to the floor and then unscrew the hatch over the tank. I had the tank in my 18' replaced due to both age and capacity. I replaced the original tank with a 50 gallon tank rather than the little one that came in it....which I nearly ran dry on a number of occasions.

[saltflyer]

That's all good info. Thanks again.