Is there a chemical answer to black water tank?

[gaston]

Peggy has offered to help me (thanks Peggy ) I have very limited internet and no phone so I will need to contact Peggy when I get home .

Yesterday I checked all hoses no leaks no smell .When I flush the smell was worse but then settled down .
I added 1kg Napisan to 100liter tank 1/8 full (sodium percarbonate) and today no smell what so ever .This was a temporary measure till I talk it over with Peggy

 

[Mischief]

I would contact Marine Sanitation in Seattle Washington and chat with them, but they are a lot closer to me.

 

[gaston]

I would contact Marine Sanitation in Seattle Washington and chat with them, but they are a lot closer to me.

 

[JDCAVE]

Some good ideas introducing oxygen is a winter project but Im still looking for a chemical answer to black water tank? ??????????

There is a chemical answer: freshwater. And you’ll probably have to change the lines as well.

 

[Comodave]

Even using freshwater and not enough oxygen the tank will stink. You can add chemicals, but the real solution is add air. We did the Groco Sweetank and never added any chemicals at all for 9 more years that we owned the boat without any stink.

 

[BruceK]

Even using freshwater and not enough oxygen the tank will stink. You can add chemicals, but the real solution is add air....

The real issue is fecal matter. Govts insist each boat become a sewage processor, something Govts have huge trouble managing, judging from the raw sewage pumped into bays and beaches here whenever it rains.
Gaston, I hope you find a solution. The kilo of Napisan you added should start the process nicely, meanwhile if we see you out we`ll anchor upwind.

 

[gaston]

The real issue is fecal matter. Govts insist each boat become a sewage processor, something Govts have huge trouble managing, judging from the raw sewage pumped into bays and beaches here whenever it rains.
Gaston, I hope you find a solution. The kilo of Napisan you added should start the process nicely, meanwhile if we see you out we`ll anchor upwind.

Hi Bruce the Napisan is making the boat smell like a baby's bum only wish I did it 6 months ago

 

[Brisyboy]

Hi Bruce the Napisan is making the boat smell like a baby's bum only wish I did it 6 months ago

Gaston,

How often are you adding it - per tank full ie after each tank pump out or does it last a couple. I have exactly the same problem. Sitting in the cockpit after a flush sure stops any conversation.

 

[gaston]

Gaston,

How often are you adding it - per tank full ie after each tank pump out or does it last a couple. I have exactly the same problem. Sitting in the cockpit after a flush sure stops any conversation.

I'd say there was 1/4 tank say 25liters that had been there for 2 weeks cooking 6 hours after dosing its sweet as roses .


https://www.ebay.com.au/itm/122905004934

 

[gaston]

Gaston,

How often are you adding it - per tank full ie after each tank pump out or does it last a couple. I have exactly the same problem. Sitting in the cockpit after a flush sure stops any conversation.

The good thing is you realty do know your true friends

 

[what_barnacles]

Even using freshwater and not enough oxygen the tank will stink. You can add chemicals, but the real solution is add air. We did the Groco Sweetank and never added any chemicals at all for 9 more years that we owned the boat without any stink.

question: Did you need to modify the tank vent to run to both port and stbd? I havent seen too many boats with both sides vented. (check their illustrations)
https://www.groco.net/products/marine-sanitation/sweet-tank-odor-prevention

 

[dhays]

I have known plenty of folks who have installed Sweetank with only one vent, not port and starboard and had no problems.

 

[Comodave]

A Sweetank works with one vent just fine. The two vent arrangement is for natural air flow through. If you are replacing a tank, I would go with two large vents. If using the existing tank, I would install a Sweetank or make something similar. I put in a Sweetank and it took about 45 minutes to install it. Only hard part was pulling thr trigger to drill a 2” hole in the top of the tank... After 2 hours the stink was gone completely. I did install it when my dock neighbors were gone because the first 2 hours were quite stinky until the aeration was complete.