Butane lighter gas system was not chosen based on the following reasons:
1) Very limited number of ballast blows
2) every surfacing cycle makes the butane lighter tank LIGHTER giving more & more positive bouyancy very fast.
3)Need to buy lighters, unless you father owns a cigarette shop
4)Dealing dangerous inflammable gas without licence,breaks the fire hazzard by-laws[X(].
5)Your kid might take the lighter out & burn down your house [:@]
6)Polluting the pond water, your fish come to the dinner table tasting smoked
Did I emphasize enough ?