Drying it
The basic principle of float-tube maintenance is to dry it thoroughly after each session and store it in a cool place. It's best to keep it slightly inflated, but there's no need to worry about storing it folded in its bag. This won't wear it out prematurely, and it won't show any creases; it'll just return to shape once inflated.
The important thing is not to leave it in the boot of a car during heatwaves, or when it's freezing. This will prevent the PVC and fittings from working and being affected by temperature changes.
Wash with clean water
A clear water rinse is the second basic maintenance step for a float-tube.

Of course, you don't have to do this every time you return from a session, unless you're using it at sea, but every now and then, to remove impurities, is the minimum. To make washing easier, you can use the same soap you use to wash cars, plus a soft sponge.

What's more, this rinsing prevents bacteria or algae from being transported from one body of water to another, and thus contaminating the environment.
Applying a PVC treatment
In the car and boat detailing aisle, you'll find products perfectly suited to PVC maintenance, applied with a pad.
As the float-tube is used on the water, you just need to make sure that the product used is not harmful to the environment. In the case of boat maintenance products, they meet this need.

These products are perfect for maintaining your float-tube, because in addition to washing effectively and removing contaminants such as hydrocarbons, they leave a protective coating.
This coating protects the float-tube from UV rays, nourishes the PVC to prevent it from drying out and cracking, and facilitates cleaning by improving the PVC's water-repellent properties. This treatment takes very little time, and can be carried out several times a year.

Inspect and predict repairs
Finally, all these operations allow you to inspect your float-tube, and spot potential snags, scratches or delaminations, which could lead to leaks. It's best to repair and solidify them right away, before they become a problem.