480 Sedan Bridge Common Drain Clogged

[steve4566]

I think that the common drain on my 2001 480 Sedan Bridge is clogged. I'm getting significant back flow through the sump pump back into the lazerette sump and a little backflow through the forward bilge pump into cabin bilge. That leads me to believe the common drain is clogged aft of where the lazerette sump pump discharges into the drain pipe.

Can anyone please recommend a method of clearing the clog? Mechanical or chemical? Should I try a plumbers snake back up the drain from outside the hull? How about muratic acid? What concentration? I could pour it down the flybridge sink and let it collect against the clog?

I'm in Florida, so I've been running bromine tabs in my A/C strainers, which I thought would prevent this from occuring. Is there something else I should be doing?

Thanks very much!

 

[steve4566]

I bought a small jet nozzle, put it on a stiff garden hose and snaked it up the drain line from outside the hull. We've got very good water pressure at our marina and I dislodged and flushed out lots of growth out. But I still have water backflowing into the aft sump.