Grey Water Sumps, Pumps and Johnson Ultima Float Switches

[akio.kanemoto]

Greetings all,

I have been looking for a solution to this problem for a while now and have procrastinated long enough.

I am currently (re?)building a boat and am up to the the part where I have to make some decisions on plumbing the shower, galley sink and washbasin in the head.

Unfortunately, the relationship between the WL and the bottom of the sinks will not allow me to have a simple system and just drain overboard.

As such, I have no other option but to drain to a sump. The good news is that I have a low enough spot that I can drain all three into the one sump.

I understand that grey water sumps are the most ghastly of all and will eventually be clogged with grease etc so I am wondering what is the best way of:

a. pumping it out
b. automatically turning on the pump

For (a) I am trying to standardize all the pumps on the boat - and am leaning towards the Flojets for most things, however for the grey water pump - I am leaning towards the Whale Gulper - for which the advertising material implies that it is "unblockable". So long hair from the shower, with bits of grease/food from the galley etc should theoretically not bother it.

Any thoughts on this? Choice of pump/blockable-ness/experiences?

For (b) - as the sump will be in a less-than-ideal place and is not easy to reach (service) - I am looking for an idiot-proof, hands-off solution (as much as possible..). The idea of float/mechanical switches in such a nasty environment isn't appealing, so I have found the "Johnson Ultima Float Switch":

Johnson Pump

"Detector cells are totally sealed, are never in contact with the water, will not corrode and are not affected by oil or foreign debris."

Does anybody have experience with this switch? Exactly how much is it "not affected by foreign debris" (quarter inch of grease build-up on the switch? 1/2"? 1"?) - is this going to work for me in my application? Are there any better ideas/switches?

Thank you all and I look forward to your thoughts!

//ak.