There are loads of sites just try Googling 'watch h20 just add water online' and take your pick
Try the link below.
you can watch i think most of them online athttp://www.yidio.com/show/h2o-just-add-water
You can watch it on Hulu.com/h20-just-add-water
watch online through http://www.yidio.com/show/h2o-just-add-water
through http://www.yidio.com/show/h2o-just-add-water i think
If you want to watch H2O just add water (fabulous show) online then just go to teennick.com and go to shows and look for H2O, once you find it go to their page and click on videos. It'll have all sorts of random videos and episodes that you might have missed.
If you are in England you can watch h20 just add water on nickelodeon or you can watch it in youtube just tipe down h20 just add water season 3
H20 just add water is not on a channel in the US, but it is in New Zealand. If you are disappointed by this answer you can always just watch it online at www.teennick.com.
you can watch most of the episodes of season 1 and 2 at http://www.yidio.com/show/h2o-just-add-water and season 3 isn't out yet, here in NZ anyway
i watch it on netflix but youtube.com will work also.
H2O: Just Add Water can legally be watched via Hulu and DailyMotion.
Search: H2O_ Just Add Water 1x14 Suprise - Veoh - Video Search
free-tv-video-online.info search h2o just add water :)
I think it's on youtube.
You can watch h20 just add water on Nickelodeon.
TVduck.com, or You Tube.
No but you can watch it on Hulu.com
You can watch it on Hulu.com Just type in "H20 just add water" in the search box at the to right hand corner