The description says that it should be properly soaked and then fits into the crown from the filter.
It happened to me that I have put him about 3 hours in a water bowl and he has indeed taken water, but not fitted properly, or was too small.
If you pressed a bit here, as you would press his sponge for washing up in his fist, all the water, then it sucks a lot faster full. Of course you should always deal more gently with this, as with the household sponge for washing, because this is supposed to filter at least 6 months.
By pressing one saves a lot of time and has after about an hour a soaked sponge, which fits perfectly into the crown from the filter.
