rotten egg smell in fresh water tank

Joined
Aug 14, 2024
Messages
15
Fluid Motion Model
C-30 S
Hull Identification Number
FMLC30291819
Vessel Name
Aquarius
MMSI Number
338391043
We have a horrible smell coming from our fresh water we can not get rid of. Our head has a fresh water conversion. We have drained and treated the tank, added vodka. Nothing is working. Help!
 
We have a horrible smell coming from our fresh water we can not get rid of. Our head has a fresh water conversion. We have drained and treated the tank, added vodka. Nothing is working. Help!
Can you provide more details about the conversion? Was this a kit from the manufacturer or accomplished in a different way? What is the model of marine toilet on your C-30S?
 
Can you provide more details about the conversion? Was this a kit from the manufacturer or accomplished in a different way? What is the model of marine toilet on your C-30S?
Our Cutwater dealer in Bellingham WA made the conversation when we bought the boat in 2020. Not sure of the model.
 
Our Cutwater dealer in Bellingham WA made the conversation when we bought the boat in 2020. Not sure of the model.
I have read about some installations where the conversion was done without adding a proper vacuum break, which can allow for blackwater contamination via backflow. Also some installs have done a "conversion" with a Y-valve allowing switching between fresh water and salt water. I'm skeptical of that approach, too. It would be helpful to understand what your system is in order to understand if there could have been some failure leading to ongoing contamination of your fresh water tanks, given that you have tried draining and treating the tank, and it isn't solving the problems. You may also want to purchase a water bacteria test kit.
 
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Thank you for your reply and suggestions.
 
I bought a used RT from Canada... fresh water boat.
I owned the boat for 2 months before I go around to running the raw water hose in the stern of the boat. It smelled exactly as you described - rotten eggs. I did some research and apparently "Fresh" water goes bad before salt water... anyway, did you run a small bottle of bleach through the system? And, I learned to add a teaspoon of bleach whenever water is added to the fresh water tank. Thus far, my water smells a tad bleachy but never bad.
 
StarBrite Water Treatment and Freshener works wonders at preventing the foul smelling water.
 
Check the screen on your fresh water pump. When we got our boat the water smelled and tasted bad. Found black crud on the pump screen. Cleaned and disinfected it and the tank. Never had a smell since and the water tastes fine.
 
I bought a used RT from Canada... fresh water boat.
I owned the boat for 2 months before I go around to running the raw water hose in the stern of the boat. It smelled exactly as you described - rotten eggs. I did some research and apparently "Fresh" water goes bad before salt water... anyway, did you run a small bottle of bleach through the system? And, I learned to add a teaspoon of bleach whenever water is added to the fresh water tank. Thus far, my water smells a tad bleachy but never bad.
Thank you for your reply. We are going to try bleach as we have read that is the best way together rid of the smell.
 
StarBrite Water Treatment and Freshener works wonders at preventing the foul smelling water.
Thanks! Ordered some today. 🙂
 
Check the screen on your fresh water pump. When we got our boat the water smelled and tasted bad. Found black crud on the pump screen. Cleaned and disinfected it and the tank. Never had a smell since and the water tastes fine.
Thanks for the tip! Will check out the screen.
 
Suggest getting the "Small" bottle of bleach. Fill the tank, pour the bleach in... let the pump run and open all the spigots - don't forget the shower... until empty. Fill the tank with water and again run the water out... if you do not run the water out a second time the water will be way too "bleachy" and the water comes out "frothy". Fill the water tank a 3rd time - good to go.
 
Prior to our R27 OB, we owned a 42 foot ketch with 200 gallons of fresh water in three tanks. Every Spring we filled the tanks with diluted bleach and let the water sit for a week. We drained the tanks and refilled. We never had smell issues and we drank the water after filtering.

Fresh water does go stale and the dilute bleach solution (formula available on RV / boat sites) shocks the water. Moreover, it can also kill most bacteria, etc). Cleaning the pump screen periodically also helps,
 
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