I just ordered the Woder 10K Gen 3 filter. It will fit under the sink attached to the cold water side of the kitchen faucet in our Isata 3. We will be able to get good filtered drinking water from the cold side of the faucet. I read the stats on the Woder & it looked pretty good. $100 from Amazon.
Of course we'll keep the whole house filter that came with the motorhome.
Happy camping.
Dave
Woder 10K-Gen3 Ultra High Capacity Direct Connect Water Filtration System - Under Sink Filter Premium Class I