we dont get any tcp taste as we rinse throughly with several changes of water, but i do find that the water from around the harrogate area is very bad for the taste of tcp
Puriclean is the best solution for sterilising water pipes and tanks etc. for fresh drinking water as the product is also designed for water tanks on marine vessels and boats. Sailing out on the ocean you can't just nip to a water tap every day to fill up a bottle with fresh drinking water so it proves it's safe. You can see more about the product and the bio-film it destroys in the link below.
I fill the tank and system using a "white" water hose and purify everything then flush it out and refill with fresh, i have an inline filter that serves the "kitchen" tap and filters to drinkable. Its recommended that the filter is changed every 4500 litres or yearly whatever comes first, changing is a five minute job using push-in connectors.
I used to drink water from the tank on my boat, but it did sometimes have a bit of a taste to it from the purifier I used. The other thing was though that on really hot days it didn't come out cold, which is one of the main reasons we now fill a separate container with drinking water and put it in the fridge. If we are having a hot drink we do fill the kettle from the caravan's kitchen tap.
Clean the tank twice a year with Puriclean then add Aquasol every time you refill the water tank. Drain the tank at the end of every trip. We have never had any problems with drinking the water following this regime