It's a long answer, and we all have learned more since my last response. If you want the short answer, it is yes, but....
The basic rule of thumb is 1 gallon per minute (GPM) is required for every 4,000 Btu’s of capacity. So, 9,000 * 3 = 27,000/4,000= 6.75gal/min * 3.785=25.55liters/min * 60 = 1,532 liters/hour OR, 6,75GPM * 60 = 405GPH. The March AC5-C-MD is rated at 1000 hal/hr (GPH), which is more than twice what it should be rated at. However, as you know, when all 3 ACs are running, the salon gets its required saltwater from the output of the aft AC, which has been heated because of heat transfer. And the fore AC gets its required saltwater from the output of the aft AC and the salon AC, which has been heated because of heat transfer. I really do not know how to take all of that "pre-heated" water into account.
All of that said, the Calpeda pump is rated at 4.8 sq meters an hour or 1268GPH. So the
March AC5-C-MD pumps about 25% less water than the Calpeda, but substantially more than the rule of thumb requirement from above of 405GPH. Coastal Climate Control recommends the March TE 5.5C-MD-AC, which is rated at 1500 GPH, and 50/60hz.. Mark on CREAM PUFF installed this pump and is satisfied with its performance. I think the safe thing to do is use The March TE 5.5C-MD-AC
I hope this helps you and others with this decision.