How much water does the medium hold?

The medium reservoir holds about 1.5 gallons (roughly 6 liters), enough for a medium dog or a few small pets for a day or more depending on how much they drink.

Does it filter the water?

No. It is a gravity feeder with no pump or filter, so water sits in the bowl until your pet drinks. Change it regularly and clean the parts to keep it fresh.

Is the bowl dishwasher safe?

The stainless steel bowl can usually go in the dishwasher. The plastic reservoir and base should be hand washed, since heat can warp them.

How often should I clean it?

Rinse and refill the bowl daily and scrub the reservoir and base at least weekly. In warm weather or with messy drinkers, clean more often to prevent slime.

Is it good for large dogs?

It works for medium dogs and multi-pet homes. A very large dog may empty the bowl faster than the reservoir refills it, so a bigger model may suit better.