Water Smells In Freshwater Tank:

magicalbill

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As the title describes. The 30 gallon freshwater tank on our Marlin started to smell lousy in September when I put her up for it's Long Winter's Nap. I can only imagine what it will smell like in June 2022 when we get her out of climate controlled storage.

So, what do y'all recommend to solve the problem? I thought of just running the hose into the tank for awhile to flush out the old water; Any cleaning solutions/procedures that work better?

Thanks and hope everyone had a good Thanksgiving.
 

DennisG01

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Honestly, I would take care of this now. Who knows what might grow in there if you wait. Winterizing a fresh water system is pretty easy and straight forward so it's not like it will take much time, either. Put about a half cup of bleach and 15 gallons of water in there. Check your water filter at the pump and remove/clean it. Turn on the system and pump the solution through all spigots. Let it sit for 24 hours and then run it dry. Add a few gallons of water and again run it dry. Continue flushing until you're satisfied the bleach is well enough gone.

Do you have a HWH? Don't forget to do that, too - just mentioning that in case you bypassed it for the winter.

In the future, use the water on a much more regular basis -- and it wouldn't be bad to use an additive to help keep it fresh or even just a few capfuls of bleach each time you fill up.
 

SkunkBoat

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every year I flush it /bleach it out. fill it. NEVER use it. Empty it of stinky water. put in some RV antifreeze. ....repeat every year

My boat has 3 sinks... THREE!.... WHY? I can almost put a hand in two sinks at the same time. never use them. two are full of fishing tackle.

I use washdown..or reach over the side....and wipe my hands in my t shirt...


Don't just let it run into the tank.
you gotta spray it in there hard to breakup the brownish pink bacterial slime.
You'll see it floating out of the fill....
 
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seasick

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I like to put the hose nozzle in the fill and fill until it overflows out of the fill. Let that run for a while and you will probably see gunk float up and out. The bleach as Dennis mentioned will do a good job but if you don't use the water very much or live in hot climates, add a smaller dose of bleach to each tankful. For the initial cleaning, I would use more bleach that Dennis recommended but you can experiment and start out with less. Obviously, you can't drink the water and should keep in mind that the higher dosages of bleach can bleach the color out of clothing and fabrics.
Also make sure to check any inline filters or screens for gunk and also any aerators in faucets.
 

DennisG01

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Was just about to add something about the aerators and Seasick already commented on it. But... yes, remove those ahead of time and leave them off while you're doing the flushing. I wouldn't remove the filter, though - just keep checking it - no reason to purposefully allow the gunk (or more gunk, as it may be) to go into the lines.
 

magicalbill

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Hey All:

Thanks, as always for the helpful replies.

I don't think I can even get to the boat now. it's 330 miles away in Northern Michigan, buried who-knows-how-many-boats deep in climate controlled storage. I'm almost certain I can't get a hose to it.

I use the fresh water fairly frequently during the 2 month season up there. it's the long period of inactivity associated with the winter months that's the problem.

I will certainly utilize the bleach in the spring and do as Dennis & Seasick recommends.

Skunk:

The three sinks, (which I have too) are for us cruisers; I can see they'd be of no use to you guys. We use all three when we overnight. My Sig Other cooks in the galley, we also use the head sink, and I use the freshwater spigot in the stern.

Thanks for the RV antifreeze tip..Is that better than bleach? I'll use whatever is the most effective.
 

Halfhitch

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RV antifreeze is just that. It causes water to freeze at lower temps than normal. Bleach is an anti-bacterial you might call it. Kills all sorts of bad stuff...including you if you get too much. It's chlorine in a very reduced state. Myself, I found RV antifreeze harder to get rid of as far as taste so if you don't have the ability to flush easily, then using air pressure to dry the lines is better if you know you will be in dangerous temps.

When I get back from a trip, I turn on the freshwater pump and let it pump out while I"m washing and flushing the boat. It keeps the water from getting rank. I keep my boat at home though so it's very easy to refill before the next run. I know not everyone has easy access to good water all the time.
 
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gbgrady208

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The Great Grady app says to flush once or twice per year with water and a 10% bleach solution to kill mold and mildew. 10% is the same that we use in EMS to clean medical equipment in the field and on ambulances. And, it also says to add lemon juice to the water tank to help control odors. Lastly, it says "This is NON-POTABLE water system. DO NOT DRINK". I've never tasted the water on my Marlin 300 and glad to see this warning as a result of looking this up relative to this forum thread. I also filter my water with a hose filter when I'm filling it - - bought the same one that I use for our camper van which is water we do drink. They are inexpensive and will keep solids and some chemicals out of the water system which should help control odor once you get it cleaned out with the bleach solution. I don't trust the water at the marina, so I also filter not knowing how bad the water might be in a rusty saltwater environment.
 

nuclear

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As other's have said, you need bleach. Had the same issue with the tank on our 228 when we bought it, water must have been old. I drained it, refilled with water and bleach, drained again, etc. Good as new. We don't use the water much though so I make sure it is empty whenever I get back to the dock. Gives my kids something to do, they spray everything down in the back.
 

DennisG01

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Just a side note, with the cruisers that I've owned in the past, I've always used either a couple capfuls of bleach or a specific water sanitizer additive throughout the season and never had an issue with the fresh water holding tank. We drank the water, too. It's good "PM" to use something - unless you're going through the water very quickly then it's probably not necessary. The only problem I even had was one season where we went a long time between uses of the hot water tank - that one got smelly. But the above remedy fixed it.
 

everwhom

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I find that I need just a couple of ounces of bleach in my freshwater tank to eliminate any of that bad smell. I keep a small bottle on board and I just pour a little into the tank at the beginning of the season when I fill the tank. I never drink the water, though!
 

Fishtales

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10:1 water to bleach solution and let it sit in the tank for about 30 min. Then work through each freshwater opening. Fill with water and repeat. I never drink the water but it is needed for the vacuflush and any freshwater clean up.
 

magicalbill

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Continuing thanks to all who took the time to respond.
 

magicalbill

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I'm thinking the bleach advice and I'm intrigued by the West Marine Water Tank Flush Cleaner that Ponquogue mentioned.
 

Mustang65fbk

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The Great Grady app says to flush once or twice per year with water and a 10% bleach solution to kill mold and mildew. 10% is the same that we use in EMS to clean medical equipment in the field and on ambulances. And, it also says to add lemon juice to the water tank to help control odors. Lastly, it says "This is NON-POTABLE water system. DO NOT DRINK". I've never tasted the water on my Marlin 300 and glad to see this warning as a result of looking this up relative to this forum thread. I also filter my water with a hose filter when I'm filling it - - bought the same one that I use for our camper van which is water we do drink. They are inexpensive and will keep solids and some chemicals out of the water system which should help control odor once you get it cleaned out with the bleach solution. I don't trust the water at the marina, so I also filter not knowing how bad the water might be in a rusty saltwater environment.
I was just thinking... what about using distilled water instead of tap water, from a hose, at a marina or so forth? I still wouldn't want to drink it but would that help with less mold or other bacteria growing in the water and getting the funky smell in the tank? I'm sure it wouldn't be fun trying to figure out how to get 30 gallons of distilled water into the tank. But for the smaller boats like my 228 Seafarer that only has a 10 gallon tank, that wouldn't be too difficult to manage if it meant less maintenance or problems. Just a thought...
 

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We use our freshwater system mainly to rinse off from snorkeling and such or when we are trolling it's nice to cool off with a quick spray to the face and head and neck. I treat it like I treat my camper water holding tank. Winterize it with rv antifreeze and in the spring flush it all out with fresh water , do the bleach thing and look up how much bleach per gallon to use to treat it to portable standards .

We don't drink it either but I try to treat it like my camper in case in an emergency I need to drink it. Heck I have been backpacking over the years and I treat my water in the Backcountry but I suspect I could easily have gulped some bacteria and stuff over the course of my life.
 

DennisG01

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I was just thinking... what about using distilled water instead of tap water, from a hose, at a marina or so forth? I still wouldn't want to drink it but would that help with less mold or other bacteria growing in the water and getting the funky smell in the tank? I'm sure it wouldn't be fun trying to figure out how to get 30 gallons of distilled water into the tank. But for the smaller boats like my 228 Seafarer that only has a 10 gallon tank, that wouldn't be too difficult to manage if it meant less maintenance or problems. Just a thought...
Pouring a capful or two of bleach (or water additive) into the tank is a WHOLE lot less time consuming than continually buying/lugging gallons and gallons of distilled water! :)

If you keep the water clean and treated, there's really no reason it can't be drank. There are LOT'S and LOT'S of us folks with cruisers and RV's that drink the water, make ice from it, cook with it... Not to knock anyone that doesn't want to - but it IS totally, and safely, doable.
 

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I did some research a long while back and for normal water state during season, it was recommended to use 1.5oz bleach to 30 gallons. This is drinkable, but I would not do it. I just use water bottles to quench my thirst. The water has a very slight smell of bleach, much like the city water we have.
I empty the water tank in the fall for winter and pour in 2 gallons of West Marine's Antifreeze and flush through all lines/sinks.
In spring, I empty the tank first, then fill with water, empty and repeat this 2 times to clear out the Antifreeze. Then I refill and add the 1.5oz bleach and am ready to go.
I do like to use soft water to fill the tank to keep minerals from building up on the faucets, but this is not a necessity unless you have some really hard or bad water .

With this method, I have no issues and feel that in a pinch, I could drink the water without worry of bacteria issues.
 

jip40

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The Great Grady app says to flush once or twice per year with water and a 10% bleach solution to kill mold and mildew. 10% is the same that we use in EMS to clean medical equipment in the field and on ambulances. And, it also says to add lemon juice to the water tank to help control odors. Lastly, it says "This is NON-POTABLE water system. DO NOT DRINK". I've never tasted the water on my Marlin 300 and glad to see this warning as a result of looking this up relative to this forum thread. I also filter my water with a hose filter when I'm filling it - - bought the same one that I use for our camper van which is water we do drink. They are inexpensive and will keep solids and some chemicals out of the water system which should help control odor once you get it cleaned out with the bleach solution. I don't trust the water at the marina, so I also filter not knowing how bad the water might be in a rusty saltwater environment.
My notes from someplace Grady has the ratio at 2 pints of bleach to my 50 gallon water tank - your recommendation would have me using 5 gallons of bleach - one of us is far off