Increasing Spectra 150 output with booster pump

[SV Liberty]

Hi all,
I am considering the following: I have a Spectra Ventura 150, manual unit (no MPC controller), that has a seawater strainer and 5 micron filter before the Spectra Jabsco feed pump. There is about a 24" head (give or take a few inches, I'm off the boat for a bit) from the through-hull to the feed pump head. I installed a rebuilt Clark pump from Spectra about 2 years ago and replaced the feed pump head about a year ago. Output has been around 5 gpm or less, and no higher when voltage is up. Water quality has been a bit variable, and I am planning to replace the membrane (it is at least 7 years old). When I sent in the Clark pump for replacement one of the cylinders was scored.

I'm considering the following: in-line between the sea water strainer and the 5 micron filter housing, adding a 20 micron filter housing and a booster pump of some sort, in that order (so it would go thru-hull, sea water strainer, 20 micron filter, booster pump, 5 micron filter, Spectra feed pump, Clark pump).

Anyone (Tellie?) have thoughts or experience with the foregoing? Thanks in advance.

Dave

[Tellie]

Hi Dave. Yeah that would be over kill and it would not gain you any extra production or protection. The single five Micron pre-filter is all that is needed. Even the next two larger systems have only one five Micron filter, an extra 20 Micron inline is not needed. The Spectra feed pump on the 150 is made by Shurflo not Jabsco, are you sure you have the right feed pump? A boost pump would not make a difference either as it would not add any significant pressures or flow. The feed pump head is designed to be installed up to 36" above the waterline. If you're 24" above the thru hull itself you're well within the limits. The 7 year old membrane might be the issue of 5gph if it is fouled somewhat. The only true test to be sure is to do a flow test. The VT 150 is rated at 6.5gph and usually does 6.5-7.5, 5gph is certainly a sign something is wrong somewhere. First make sure your feed pump is a Shurflo and that you have the Spectra replacement feed pump head, anything else won't work. Also do a quick pressure test on the feed pump head by pinching off the brine discharge line. The pressures on the guage should quickly rise to 120-130psi and if it's the proper head it should cut in and out via the pressure switch. If it does this and the flow test checks out then I'd suspect the membrane. You can always PM me if you'd like and I'll give you my cell number. Sometimes it's more efficient to talk these problems out over the phone while you are at you unit then post the results here. Best of Luck

[SV Liberty]

Thanks much Tellie. The pump is a Shurflo (I just mis-remembered). I did install a new pump head I bought from Spectra, so I know that's all good (assuming I did the head replacement right, and I think I did). I plan to replace the membrane when I recommission the boat (its on the hard in St. Martin now) in a month. I will check it all out then. Appreciate the advice on not trying to monkey with the system. Will try to remember to post results after recommissioning and membrane replacement.

[Tellie]

No problem. Installing the feed pump is pretty straight forward so I'm sure you have it right. Let me know if you need any help when you're ready to install the new membrane and start it up.

[Pirates]

Originally Posted by Tellie

No problem. Installing the feed pump is pretty straight forward so I'm sure you have it right. Let me know if you need any help when you're ready to install the new membrane and start it up.

Hi Tellie,

Jim here. Having a problem with my spectra. Is it possible to call u to discuss.

Thanks

Jim
S/V Pirateboat. Turks and Caicos Islands


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