I believe that the Calpeda pump may be slightly underrated when all 3 compressors are cycling ON...AND, the March pump that Ben installed is slightly less than the Calpeda pump. However, in my experience you will rarely turn ON all 3 ACs, and even more rarely, will they all cycle ON at the same time. Slightly undersized AC water pumps will result in slightly less cooling capability when all 3 compressors are cycled ON. 

I like the Calpeda pump and both versions of the March pump mentioned here, but for different reasons. I like the Calpeda pump for its quality and durability. This pump will likely last 20 years with only capacitor and mechanical seal failures...each easy to repair...that is hard to beat in a saltwater pump. If the mechanical seal fails (evidenced by water dripping) and it not immediately replaced, the bearing on the pump side of the motor will also fail. And, of course, I love the magnetic drive of the March pump. I believe the March pump that Ben mentions can be a good substitute for either the Calpeda pump or the LP pump for a 160 liter Dessalator.

Here is a "PEARL" of information. The pump Amel used is the Calpeda BCM 20E "Tropicalized." I am not sure about all of the "Tropicalized" modifications, but one is that the non-Tropicalized BCM20 comes with a plastic capacitor. In the tropics, you need a aluminum capacitor, that comes with the Calpeda BCM 20E "Tropicalized" pump. I became aware of this because an Amel School client bought a SM in the tropics which had a new Calpeda pump installed...it came with a plastic capacitor, which continued to fail because of heat until it was replaced with the same rating aluminum capacitor.