I have recently bought my son a small 23 litre tank put gravel filter in and water conditioner (intrapet bioactive tapsafe) was w8ing 7 days till we get fish this is day 2 and 3 and the water has gone really cloudy I turned the filter off to see if it cleared but its still really cloudy today can any 1 help?

Quite normal with a new tank and it will clear in a day or so.
Best to leave your filter running as well.

Couple of things:

Did you wash the gravel before using it?
Do you have the charcoal cartridges on the undergravel filter?