Cucumber in water?

[appps]

We used to put half a cucumber in with our goldfish and they used to hollow out the middle eating it till they could swim inside, quite cute :-)

Only problem was after about 3 or 4 days it was enough to send a four foot tank full of water off and cloudy.

Wouldn't think it would be long before a little Hernie water dish of water would become unattractive to them due to the cucumber.