Hot water tank funky smell

[robbjd]

Stu, perhaps I didn't describe our system in enough detail. We have two pumps, one 3gpm pump that feeds fresh, clean, municipally treated, Lake Huron water from the forward tank to a single faucet/spigot at the galley sink, and a second 5.5gpm pump that takes water from wherever the boat floats and feeds the sink(s) taps, cockpit shower, and a deck wash line. The cleanup of the system was easy enough to add to my routine maintenance jobs. We also have a propane fired instant hot water heater for cockpit showers when engine or electric heat aren't available. Is that Aquavite in the attached file?

[Stu Jackson]

That makes much more sense, thanks for the details.

Yes, that's Aquavite in my avatar picture; taken at dawn on Lost Slough in the California Delta.

[Jim Hardesty]

We also have a propane fired instant hot water heater for cockpit showers when engine or electric heat aren't available.

That's absolutely decadent.  Sure would beat the solar shower bag. I'd be interested in seeing some pictures of that installation especially the chimney.
Jim   

[robbjd]

Jim, shower hangs off the stern rail alongside a 5 pound propane tank. I don't have it installed this season since we have no trips planned, just day sailing.

[Jim Hardesty]

Jim, shower hangs off the stern rail alongside a 5 pound propane tank. I don't have it installed this season since we have no trips planned, just day sailing.

Thanks, I didn't know they were made.  I'm planning a North Channel trip next season and will consider leaving the solar shower home and buy one.  As I get older swimming with soap in the cold water has much less appeal.
Jim

[Ron Hill]

Guys : I use a cap full of bleach for a full the aft tank and a half a cap full for the starboard tank.  90% of my fresh water comes from Marina wells!!

I usually draw from the starboard tank and then refill from the aft tank!!

A thought

[pbyrne]

PBYRNE, 
When the hot water gets funky on Shamrock I just flush the hot water with regular water.  Open galley sink, head sink and cockpit shower run for 5 minutes, wait, repeat a few times.  Then refill the aft water tank.
The hot water tank is not quick to flush, it's made to mix hot and cold water, opening the drain will still leave water in the tank, a few inches.

That and trying to use the hot water, even if it's not hot, as much as possible works for me.
Hope that helps,
Jim

Another thing that comes to mind.  If the lines are funky the smell would be strong at first then less as more fresher water flows.  If the tank is funky the smell would continue. 

I'll try that.  Is it safe to leave bleach in the tanks for long periods of time?  I use it to flush the system in the spring and then switch to a sodium percarbonate/sodium bicarbonate power from Captain Phab.  Basically, it introduces hydrogen peroxide into the water.

The cold water is completely odourless and clear, but the hot water.. well nothing so far.

Maybe I should just use bleach at all times...

[Breakin Away]

I know this is an old post, but I could not get time to reply sooner:

I do an overnight shock and purge every spring as soon as I launch. If I don't do it soon enough I regret it. This year I was too busy, and two weeks after launch I regretted it. In these cases, the foul odor always starts in the hot water tank. I always assumed it's because the of the heat cycling - every time you run the engine the hot water heats up, and the speeds along the growth of any minute amount of biological challenge. So it's only a matter of time. Whenever we take a trip and need to wash the dishes, we always try to use up the hot water to prevent it from brewing up any bad stuff over time.

Many people add extra chlorine to their tanks. I don't believe in that. If you're filling with municipal water it already has chlorine, so you could over-chlorinate beyond the EPA's 6 ppm limit, which could corrode metal hardware and cause brittleness in you plastic tubes, fittings, and pump impellers. So I give a hefty dose of chlorine for 10-24 hours, which isn't long enough to cause any damage.

I choose to follow Peggie Hall's recipe and instructions, which can be found here: http://www.trudelutt.com/linker/phall_freshwater.pdf

"3/4 dl of bleach per 10 liters of water" = 0.75 l per 100 liters = 0.75% v/v. Presumably, she is referring to standard bleach, which is 5.25% w/w sodium hypochlorite, so the concentration of the active ingredient is about 0.04% or roughly 400 ppm (note that this is sort of a blend of %volume and %weight, so it's very approximate)
In imperial units, this translates to 1 oz. of standard 5.25% bleach per US gallon of tank capacity (easy to remember). Multiply this by 0.88 for 6% bleach, 0.61 for 7.5% bleach, 0.45 for 8.25% bleach (be sure to read the label for concentration)]

28 gallon tank: 17 oz of 7.5% bleach
42 gallon tank: 26 oz of 7.5% bleach

• Be sure to use "plain bleach", no fragrances or anti-splash additives.
• No-name bleach is usually better than Clorox, since they often add stuff you don't want like "Cloromax" polymer additive. You want just plain bleach.
• Limit shock time to no more than 24 hours, otherwise corrosion damage or brittleness/cracking of plastic tubing, seals, and pumps may result.