Ken,

We do not have a pre-pump. I was unaware of the air issue. For the most part I do not see air in the system (via the float gauge). Once and a while there is air during the start up if the sea-chest filter is not all the way full. But, this is not the norm.

With best regards,

Mark

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Tahiti, French Polynesia

www.creampuff.us

Hello Mark,

On Aquarius, we also have this problem with our 24V D60.  We continually see an increase in the ppm each year.  I have a few questions so we might flush this out...

1) Do you have a pre-pump that feeds your high pressure pump?
2) For those that have a pre-pump, do you see this problem?

I am starting to get the feeling that cavitation do to air in the system is causing the problem on Aquarius.  We only have a single sea water intake, stock Amel, and we do make water while motor sailing, and this could cause air to get into the water-maker system.  With the air in the system I am led to believe this is like a jack hammer on the membranes causing micro tears to form.  Overtime, the holes get bigger, and whaalaa 1000 ppm.

I don't have the pre-pump on Aquarius, but I am planing to add the pump when I install new membranes in about 6 months. 

Does anyone have any thoughts about this?

Ken
Aboard Aquarius Locked Down in Phuket
SM2K#262