John,

have had the older Spectra two pump system since spring 2000. I've spent a LOT of painful time working on the feed pumps.

NOISE - the Shurflow feed pumps were originally mounted in a compartment below the floor of the lazerrette - below the waterline for easy priming and quiet running. They were mounted on rubber pads but thru bolted to a vertical bulkhead. The noise in the main cabin 15' distant was noticeable but not enough that it interfered with conversation or music enjoyment. Cockpit noise was not bad - it was noticeable but did not require one to raise their voice.

After five years I moved the pumps (more about why later) up to a vertical bulkhead right below the seat bottom in the cockpit. The pumps are solidly mounted to the bulkhead with only their rubber feet as cushioning. That move made very little difference in the apparent noise in the main cabin or the cockpit.

Getting the pumps SECURELY attached is important - if the thru bolts are at all loose you get a resonance that is terrible. I periodically tighten the thru bolts.

The real noise, the annoying noise, is the "bang" of the Clark Pump as it reverses and the shudder in the high pressure lines as the pump reverses. My membrane holder is mounted horizontally onto a shelf under the cockpit and transmits all that commotion throughout the boat. It is quite noticeable and annoying. I am not aware of any way to diminish that noise.

FEED PUMP MOUNTING LOCATION - ease of access is essential - particularly to the bottom of the pumps. You must keep a close eye on the hose clamps to ensure they are tight. Leaks are annoying but a loose clamp allows air to get into the system and really diminish the efficiency and output. I moved the pumps so the hose clamps are very easy to check. The original installation required a complete removal of everything in the lazerette and I had to stand on my head and work with only my left hand in the bottom of the compartment - it was almost impossible to do good maintenance.

EVERY hose clamp Spectra provided rusted thru in five years and eventually failed. I replaced them all with the best quality stainless clamps I could find. A failure of a clamp on a feed pump will put 1.5 GPM into the bilge or compartment containing the pump - it happened twice.

AUTOMATIC FEATURES
The automatic features, IMHO, are of no value what so ever!

I start the feed pumps and let them run for two minutes with the high pressure switch bypassed - that moves any stale water over the side. I then close the high pressure switch and leave the membrane output lined up (a valve under the cockpit seat) to discharge over the side. I let it run for several minutes until the water tastes good. I then put a sample into a clean glass and test it for salinity. If it is below 250ppm I switch the valve to put the product into the tank - if >250 I let the system run another couple minutes and test again.

It is easy and works very well.

Another important install consideration - where to put all the prefilters ( algae/plankton - 20micron - 5micron)? The filters need to be visibly inspected every time you use the system and need frequent cleaning and replacement. It is not possible to change a filter without spilling several ounces of saltwater. And - at least on my system, the impact of the high/low pressure from the Clark Pump causes the threads on the filter houses to lock. I have had some real struggles getting the housing unscrewed from their mounts because I did not leave enough room for the filter wrench to easily fit around the housing.

Spectra is a great system - mine is still working perfectly after 11 years.