You can use Yellow Magic to safely clean the tanks and pdms layer then rinse with clean water. If you have an air blaster you can blow the water off to avoid spotting.
I tape all my tanks which has saved me from catastrophic spills if the tank decides to crack. Because the tanks have a bottom window glued in and the sides are acrylic they do wear out. I watch for any cracking on the tank. Usually on the back left corner is the most frequent spot but cracks can come from the clear insert that is glued in. The tanks do flex a little bit when printing especially with large prints and over time tend to break down the glue joint. Keeping that in mind I wouldn’t do more than a couple liters through a tank. If you do light small prints then chances are the tank will last longer but consider it a consumable.
If you plan on keeping permanent tanks and do your own recoating then consider the Zvat which has a glass bottom. I believe you get about 5-6 coatings out of a Sylgard kit so having a few tanks to cycle through would be ideal. Really depends on the volume of prints you plan on doing to justify the investment.