how to clean fresh water tank

[cabos]

Hi,
I got little white rocks in my fresh water tank. Hunter passage 42. these rocks keep on blocking the water for passing through. what should I do?
thanks,
Gil

 

[Stu Jackson]

do a search on the word recommissioning, you'll find the answer.

 

[zeehag]

Hi,
I got little white rocks in my fresh water tank. Hunter passage 42. these rocks keep on blocking the water for passing through. what should I do?
thanks,
Gil

sounds like calcium crystals. try vinegar instead of clorox in the recommissioning.

 

[Peggie Hall HeadMistress]

Recommissioning won't solve this problem

Recommissioning sanitizes the system...his may need sanitizing, but right now he has a more immediate problem: draining "sand" that's clogging the tank discharge. Substituting vinegar for bleach wouldn't accomplish anything, 'cuz vinegar needs to be undiluted to dissolve mineral buildup Besides...we don't have a mineral BUILDUP here...the crystals are loose, blocking the discharge fitting.

I'd try disconnecting the water pump...put a pan or a bucket under the discharge hose and try to drain the sand...if it clogs up the hose, stick a screwdriver blade into it to un- pack the sand and gravel. I wouldn't just let it drain into the bilge, though..doing that could clog up the bilge pump(s).

 

[BobM]

What's the tank made of? A stronger acid than white vinegar (a weak acid) may be the solution. Get some of the rocks and do some table top experiments with dilute muriatic acid. White household vinegar is 5-8% acetic acid and about pH 3 where even a dilute 5% solution of muriatic acid is closer to pH 1. Solubility is pH driven, once you are at a pH and you are dissolving basic solids and hence neutralizing the acid and need more acid you are talking buffer capacity. So you don't need to push the acid concentration really high in consequence if the contamination isn't significant (just small rocks).

In any case, be sure to flush the system well and to be aware that is also dangerous to use higher concentrations of hydchloric acid, especially if you have put any bleach in the water tank, as it will evolve the acid as a dangerous acid gas.

Alternately, a physical means, like using a thin tube attached to a shop vac might be the best approach.

http://answers.yahoo.com/question/index?qid=20100423183854AAjldbA

Bob

 

[Paul Cossman]

I've got a 1991 P42 with the same problem. I've never been able to completely clear the tanks of the stuff, and it eventually clogs up my filters in my fresh water system. So I just keep cleaning out the filters. Not too big a deal.

BUT it sometimes clogs the lines where they connect to both the forward and the aft water tanks. After much pain and experimentation, I've developed a system that works reasonably well. I have a PVC "T" fitting right next to my water pump with a threaded cap on the end of it. I also have a 12" flexible hose with a threaded female end on it. When the line is clogged I unscrew the cap, screw on the hose, and blow in the end of the hose until it dislodges the crystals that are blocking the outflow from the tank. It's easy, takes only a minute, and solves the problem for quite some time.

If anybody can tell me how to totally dissolve all the remaining crystals, and the stuff adhering to the insides of the tanks that causes them, without destroying my 20-year-old tanks, I'll be your friend forever.

Cheers,
Paul.