What is the potential problem for robotic rovers on Mars?

Explanation:

Difficulties and hazards include radiation exposure during a trip to Mars and on its surface, toxic soil, low gravity, the isolation that accompanies Mars' distance from Earth, lack of water, and cold temperatures.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

i would think it's dendrites