T&T: Watermakers: anti-freeze AND/OR biocide?

[Milt Baker]

John,

I'd never heard of using pink anti-freeze to lay up
a watermaker, but it makes sense to me so I called 
Village Marine Tec today and asked them about it.
Their recommendation is that for winter time layup
one should use BOTH the pink anti-freeze (such as 
the Seafit polypropylene glycol blend in the West
Marine catalog) and the usual biocide.

Seems to be the likelihood of anything growing in
a watermaker system filled up with the pink stuff is
very low, making it unnecessary to use biocide
too, but that's not what Village Marine recommends.

I'm wondering what your real world experience 
using only the pink stuff is and whether anyone else
has experience with this.  How long have you laid up
your watermakers with the pink stuff without having
problems?

Frankly, the biocide is so strong that it seems to do
a number on fragile metal and rubber parts that all
watermakers have, and if I can avoid using it and 
and still lay up my watermaker while I am away for
months at a time I'd like to do so.

For the record, we have a VNT Squirt 600 GPD unit.

Thanks for any amplification you can provide.

--Milt Baker, Nordhavn 47 Bluewater, Stuart, FL


John wrote:

We have a Spectra on Seahorse and a  Village 
Marine on Truelove. In both cases, they are 
permanently laid-up;  filled with <pink> 
antifreeze, rather than pickled.