New control panel

Spectra Watermaker

In Boat Projects, Living Aboard, Watermaker by Volare3 Comments

Spectra Gulfstream 400 watermaker with Z-Ion flush system.
Completely rebuilt by Spectra, capable of 8gph with one pump or 16gph with two pumps operating.

Now… first off…. If I was starting from scratch and hadn’t lucked out on this used system, I would (and did) highly consider a system from Cruise RO. Rich Boren at has a wealth of knowledge about water makers, has great customer service and would help you… even if it isn’t his system. For a compact system that can be run from a Honda 2000 portable generator, give his system a hard look.

So, when my Spectra system was purchased from a guy who knew a guy…. it looked like this. (pretty rough to say the least)

Old spectra Gulfstream 400

Old Gulfstream 400

Inside of Gulfstream 400

Inside of Gulfstream 400

Yes it was old when I bought it… but Spectra has* a program to rebuild the Clark Pump to new, for a reasonable amount. (Around $500)

has* had (With Spectra being purchased by Katadyn, rumor has it that this cheap rebuild program has gone away.  Check with Spectra or your local dealer before committing to a Clark pump in need of rebuild.   I’ve read that it isn’t too difficult to do but I have no first hand experience.)

Its automatic control had long since quit. After taking the system apart to be able to stuff it into small spaces in my bilge, I turned it into a manual system. The anodized aluminum face pieces were custom cut… and they turned out awesome! They were really easy to design using the downloaded software from You just use their software to design your panel, select the material and then in a very short time they ship it to you. Very affordable…I think the first panel was about $130 made from anodized aluminum.

New control panel

New control panel

Service Panel

Service Panel. Easy access to ‘Pickle” the system

Dual Low Pressure pumps

Dual Low Pressure pumps

Finished product in the forward part of our bilge.

Completed install

Finished install

Spectra has great customer support. If you need any manual or other support items from them, just go to Spectra Watermakers

Borrowed from the web… here is a great source of information about most Spectra watermakers. Shout out to – Watermaker notes for a very comprehensive users manual.

I THINK the Z-Ion system works. But’s finicky and needs to be dialed in to each different system… and least when you’re dealing with a manual system. The concept is one derived from the space program. How to preserve water for extended storage. The Z-Ion system essentially is a carbon filter with a bottom piece that contains silver. When you flush using the Z-Ion system, it activates a charge for the water flushed through the silver. It alternates between a positive charge and a negative charge so that the end produce is both positively and negatively charged silver ions throughout your system. Spectra claims the flush lasts about 30 days and I’m slowly starting to see that. But it hasn’t been without strife. Especially with a completely manual system like mine.


The challenge is to get the correct amount of silver ions into the system. It takes a combination of both flow rate and silver. The goal is to get your flush system to just under 1.5gpm. Too much or too little throws off the balance. Second, there is an adjustment on the Z-Ion system to ‘turn up’ or ‘turn down’ the amount of silver produced. So far, I’ve only turned mine up. The goal is right about 1ppm of silver. Since there aren’t kits to measure silver, a copper test kit for aquariums is used. I’ve definitely seen varied numbers when flow rate varies.

I use a liquid test kit with a test tube. I’ve found that the plain strips that you just dip in the sample are garbage. This is the test kit I use and it’s really inexpensive. API Copper Test Kit api-cutest_

This is a good sample.

Figuring out flow rate and silver quantity is the challenge. I’ve got some numbers that I’ll post soon.

Thanks for reading! Make sure to check out the rest of our website and follow along with our travels at CruisingVolare.


  1. Just found your site. I was looking for examples of the work Front Panel Express makes. I’m looking at using them for an electrical panel on my boat, away from the main panel (and maybe redo the main panel as well). Yours looks really good. Thanks for sharing.

    1. You bet! Their free software made it amazingly easy to design and use. Good luck!

  2. Pingback: Install water recirculation valve - Cruising Volare

Leave a Comment