Living sea water hose

[KandD]

about once a month, our sea water intake chokes off, it's not the strainer, it's the 2' of hose from the through-hull to the strainer that is growing tunicates, barnacles, and hydroids until clogged. i don't know what to do, but it's uber frustrating. I have to remove the hose from the boat and run the garden hose through it to clear the line, it's not all that easily accessible either. Any ideas on how to prevent the growth?? The line feeds the engine, ac pump, head, and sink.
Thanks!

 

[Rich Stidger]

I have never heard of this issue before now.

I think I would replace the hose on the assumption that the inside surface of the hose is somehow an attractive surface or host for the growth.

 

[Rick Sylvester]

Is it

the one to port of the shaft log?

 

[Winkfish]

Can you put a strainer at or nearer to the through hull?

 

[Rob19574]

don't you close your thru-hull valve when the boat is not being used? I would think that would solve your problem by cutting off the water / nutrients supply to the critters in there....

 

[kloudie1]

I am with Rich on this one.. Something strange with the hose.. You can probably find a smooth bore hose different from what you have.. I dunno, something like a silicone liner or a teflon liner may be of use ?? Tell us what you find when you change the hose !

 

[catsailor]

about once a month, our sea water intake chokes off, it's not the strainer, it's the 2' of hose from the through-hull to the strainer that is growing tunicates, barnacles, and hydroids until clogged. i don't know what to do, but it's uber frustrating. I have to remove the hose from the boat and run the garden hose through it to clear the line, it's not all that easily accessible either. Any ideas on how to prevent the growth?? The line feeds the engine, ac pump, head, and sink.
Thanks!

A strainer will only help a little; the larve will go through.

They can attach to some pretty smooth surfaces, but a smoot hose might help.

Have you considered closing the line for 24 hours every 7 days? The lack of oxygen should be fatal. This is one reason that leaving through-hulls open can be problematic. Why should'n't they grow in a hose, afterall, since there is no anti-fouling?

Why some hoses more than others? In some cases it has to do with flow. If the line is over-size (multipurpose intake only managing AC while at the dock) there isn't enough flow to wash them out. A smaller line would stay cleaner.

 

[Ron20324]

ONE intake serves all those needs? How big is the hose? Otherwise, maybe put a tee fitting in the line and run another hose to where it is easier to connect the flushing hose.

 

[Peggie Hall HeadMistress]

Closing the seacock when you leave the boat will prob'ly go a long way toward solving the problem...and so will a screen on the thru-hull.

 

[KandD]

It looks like it may be a combination of fun, we live aboard, so water is constantly flowing through the hoses. It's a 1" black, water hose (it goes into engine compartment) that tapers to a 3/4" for the strainer. We can't get the strainer any closer, it's the water-intake just port of the shaft in the aft cabin. We have about 3" of clearance between the hull and the sole.

The sea-water system needs some re-engineering, but that won't be done until the spring haul-out. For now, we'll try shutting it off every few days and letting it go anoxic.

 

[Peggie Hall HeadMistress]

I wouldn't do that...

'Cuz when animal and vegetable sea life dies in the hose, it decays and STINKS. And when you start pulling sea water into the systems through that thru-hull, you're gonna move all the trapped dead, decaying and STINKING critters into your AC, toilet, engine intake...

Put a screen on the thru-hull and talk to your local Hunter dealer about what else to do.

You're looking for a quick fix...accept the idea that there may not be one.

 

[RichH]

This a pretty common phenomenon if youre on your boat all the time.
About every 4 months (Im on my boat 7-8 months out of the year), I blow out the line with air pressure and immediately close the seacock, then fill the line with RydLyme to dissolve the barnacles growing inside the line. Ultimately this will destroy the seacock ... but what good is a seacock if the line is clogged. The 'clear' plastic line are the worst offenders, not as bad in the black rubber lines. Water cooled refrig/freezers and AC units are especially prone to barnacle fouling .... and you dont want to be using acids routinely to clear those.

The Great Lakes sailors are PLAGUED with zebra muscles that 'really' grow inside the piping, hosing and passages ..... and since they are now soooo experienced, hopefully one of the Lakes sailors will chime in with a better way to solve this dilemma.

 

[Steve Dion]

What about putting a "tee" in the line with a couple of ball valves. You could just pour a cup of bleach or something simliar to kill off the critters on a regular basis.

 

[Rich Stidger]

K&D-

Do any of your boating neighbors have this problem? I'm wondering if the problem is location specific or unique to you.

Also, do you get growth in the metal thruhull or just in the hose? How about in the strainer?

 

[Hermit Scott]

The growth down here is insane. I scraped my hull, first time in 10 years, and these pictures are less than a month later when I moved it to haul it.

 

[RichH]

With the apparent warmer water (everywhere) seemingly causing enhanced 'hull growth', even on hulls whose bottom paint that 'formerly' gave good protection, and now not ... Ive taken up the practice of using a rubber squeegee to clean (but not scrub off) the bottom paint. The routine weekly (and quick) squeegee-ing the hull seems to have lessened the need to 'soak' the inlet hoses, probably because Ive reduced the 'population' adhering to the boat. Ive found that if I regularly 'remove the slime' I also get less barnacles overall, and I now use a bottom paint containing 'anti-slime' compounds.

 

[Rick Sylvester]

If it's like mine

that through-hull consists of an elbow and then the valve. No backing plate. No way to clean the elbow. No room to install something else.

I know this doesn't really answer your question but as I mentioned in another thread I glassed over that hole and moved it to a spot with room to accommodate a proper seacock. Now I can close the valve and clean the barb. Just something to think about for your to-do list.

As far as the hose getting clogged there may not be a good solution. The other posters may be right in changing to a different hose type improving things.

 

[KandD]

I like your setup Rick, and I'll be making that change the next haul-out. The growth is only on the hose, I may try a new hose. It's odd that it's not an issue down-stream of the strainer, maybe I have enough growth in there that they eat the larvae :dance:.

 

[Rick Sylvester]

Replacing the hose

may be your best bet for now. I couldn't swear to it but it sure seems that once a hose starts fouling badly cleaning it out doesn't last long. Who knows, maybe the critters hate the fresh rubber. I've found that once I pull out the old one it's easier to spend a few bucks and just put in a new one. Heck, if I know I'm not going to reuse the old hose I save myself the trouble and just cut it off the barb. I pulled over 50 feet of new hoses this summer. Ugh.

Good luck.