How is the urine output? Excessive urination plus excessive drinking can indicate a number of health issues such as diabetes or kidney disease. Double check with the vet on the last visit and if blood work was done or not. If it wasn't, it's a good idea to have it done now to get a baseline for future vet visits and potential health issues.
Fountains definitely need to be taken apart weekly and thoroughly cleaned and the filter replaced. Otherwise black sludge forms and can be potentially harmful to your cat And yucky sludgy water can taste bad. Most fountains are dishwasher safe except for the motor part. Hand washing can be done and you will likely need a small brush to get into the nooks and crannies.
It's good to take the fountain apart and give it a thorough cleaning every so often and change the filter.
Fountains definitely need to be taken apart weekly and thoroughly cleaned and the filter replaced. Otherwise black sludge forms and can be potentially harmful to your cat And yucky sludgy water can taste bad. Most fountains are dishwasher safe except for the motor part. Hand washing can be done and you will likely need a small brush to get into the nooks and crannies.