Can I use SMPS to power 12V DC water pump
Can I use SMPS to power 12V DC water pump


Yes. 


  I'm wary about using the brick-like power adapters as I think they are not reliable. I see that SMPS is more reliable.


Most of these power supplies are SMPS. You've got some misunderstanding there.


  One concern is that I read that a DC motor could draw upto 3 times more current while starting.


Depending on the motor, a limitation of how much overcurrent the power supply can source might or might not be a problem. For pumps, I'd expect the motor not to need overly much turn-on current, because there's most likely not much mechanical torque that needs to be generated to get the motor started. But: without knowing how exactly your pump motor works, this is all speculation.

As a general hint: if you need reliability, I don't think "the thing I found on ebay looks fine, I'll go ask electronics.stackexchange.com whether it'll work" is a good idea.