Descaling A/C 540 Sundancer

[EL PATRON]

I would like to run a descaling solution through my a/c's raw water plumbing.
I have read a number of posts on the subject. However my boat has 4 Cruisair units with all discharging raw water overboard via 4 individual outlets
I have been trying to find out how to flush the units given they all dump raw water after going through each units heat exchanger. I assume I would have to do each unit separately? If so how do I ensure the descale solution also goes through the raw plumbing connecting each unit to the raw water pump in the engine room?
Is there a way to descale all units at the same time?
Thanks

 

[ttmott]

In the 52 Sedan Bridge all of the HVAC units dump the raw water into common drains that run under the boat's gunnels. For my boat I added hose connections to the raw water pump discharge manifold (one for each HVAC unit) and connections on the discharge hose at each HVAC unit. There is simply no easy way on my boat to get to the discharge hose connection on the common drain. I can be set up and recirculating Barnacle Buster in fifteen minutes yet still keep all of the other AC units operating. A couple of pics if this helps.