There is about 3 or 4 seasons
There were three seasons (78 episodes).
You can watch H2o Just Add Water on netflix, dvd, or hulu.
watch online through http://www.yidio.com/show/h2o-just-add-water
you can watch i think most of them online athttp://www.yidio.com/show/h2o-just-add-water
season 4 has not yet been released, so you can't watch it online, but it should be shown on tv later 2011, or begining 2012
Well, you can go on Hulu.com or use the app call Hulu Plus. They have the all the episodes from the 3 seasons.
http://vbox7.com/search/?offline=1&vbox_q=h2o+just+add+water&page=4
There are loads of sites just try Googling 'watch h20 just add water online' and take your pick
There are only three seasons of H2O: Just Add Water. No its going to be out in 2012 sry =(
Yes if you have Netflics
Well it hasn't been filmed yet but when it does you should be able to watch it on nick if it premieres in the U.S. If you live in Australia then I don't know where you'd watch it. But for both you would be able to watch it on you-tube or Google it