People keek telling me to keep the drinking water clean and fresh .well i use a silo drinker but no mater how many times i change the water after the birds have been drinking out of it about an hour later the water in the bottom of the silo is all dirty again it is a good silo but even tho its a 5ltr drinker i cant keep the bottom from geting like this is this ok as i change the water every 3 days i only keep six birds but that drinker gets in some mess anyone any tips