thanks for the ideas lads ,there was one time when i just finnished picking the dog mess up and putting it down the manhole then decided to chuck the contents of two hutches of sawdust down.well it was very scary trying to chuck gallons of water down before the father saw what i just done,never again .it just seemed as though the saw dust was fighting back and was soaking up all the water i threw down. will check out these forums.cheers everyone.
good hunting
rew