Yeah on Sidereel. Its the best. Also it has the direct link to some of the best websites so all te do is click on the series, then wich episode, the choose an option.
te go in forum then click on either page 4 o 5 click on download h2o season 3 part 1 and on page 1 part 2 it's better than watching online and te can watch it as many times as u want.