Newbie: it appears tank hoses don't come with new trailer

Here's another vote for the Rhino hose. I also like the Flush King attachment, which goes between the valve and the hose and allows you to attach a water hose for backflushing the black tank.

Remember to always add some water to the black tank prior to using the toilet for #2, so you don't get a 'poo pyramid' built up under the toilet.