Mold in our poo

[SanDiegoChip]

We have just added a bellows type macerator to our holding tank (HT). In doing this we opted to have a separate hose and through hull for this. We also added a pipe into the HT for this purpose through the top.
We are live aboards on a 36’ sail boat.
When I cut the whole into the holding tank I decide to take pictures of the inside of the tank in case we ever for some reason wanted to see inside. So of course I just had to see inside. What I saw was what looks like mold in the poo. It had just been pumped out
My question is what do people do to prevent this. This is not something we want (the HT is under our bed) in the HT.
We can I suppose buy some chemicals to kill it and add them each pump out.
At the current time we have a pump out service as we are outfitting the boat for cruising south in a year.
But what later, like in Mexico, Costa Rica etc. We cannot carry a 55 gal drum of chemicals for this.
What do other use to keep the poo clean
I spared you the pic but if you want to see it….
Thanks,
Chip

[hellosailor]

Chip, you don't keep the poo clean. It is SEWAGE and by definition that is dirty and has nasty things growing in it. If you try to kill some of them, you'll kill all the critters including the ones you NEED to break down the sewage normally.

Either the tank leaks or it doesn't. If it leaks, you have a sanitary problem regardless of what you can see growing in the sewage or not. If it doesn't leak, you don't have a problem, regardless of what is in the sewage.

Don't like sleeping next to sewage? OK, move something. But unless you age it for six months and then fertilize a rose garden with the compost, it is still going to be sewage no matter what you do to it.

[dhays]

My guess is that your pump out service pumps the HT but probably doesn't do a great job of rinsing it. It is good to have the tank reasonably clean inside simply so that you don't get stuff clogging your lines or vent line etc...

I would suggest that you take the boat to a pump out station and pump it out yourself. Then fill the tank with fresh water and pump it out again. Keep doing this until you don't see anything but clear water come out as you pump it. The last time I pumped out of my tanks I flushed it 5 times.

Dave

[remetau]

I think you need to go more often.

[SlowButSteady]

Originally Posted by dhays

...

I would suggest that you take the boat to a pump out station and pump it out yourself. Then fill the tank with fresh water and pump it out again. Keep doing this until you don't see anything but clear water come out as you pump it. The last time I pumped out of my tanks I flushed it 5 times.

Another thing that helps to clean things out is to pump out the tank, fill it about 1/3 or so with freshwater, and then go sailing in some chop for an hour or so to get the water in the tank really sloshing around. After that, go right back to the pump-out station (i.e., don't give the contents much time to settle) and pump it out and rinse it a couple of times. In general, try not to leave waste in the tank any longer than necessary to keep the crud at the bottom to a minimum.

[Allanbc]

Originally Posted by SlowButSteady

Another thing that helps to clean things out is to pump out the tank, fill it about 1/3 or so with freshwater, and then go sailing in some chop for an hour or so to get the water in the tank really sloshing around. After that, go right back to the pump-out station (i.e., don't give the contents much time to settle) and pump it out and rinse it a couple of times. In general, try not to leave waste in the tank any longer than necessary to keep the crud at the bottom to a minimum.

It also helps to add dish washing soap when you do this.

[Minnewaska]

I'm not sure I would care much about this, unless I had an odor or leaking problem. If you just pumped out, that must be bacteria growing in the tank, which isn't necessarily bad.

You could always contain your use of the holding tank to "liquids only" and use shore facilities for solids for a while. That would eventually break it all down and you would pump it out over your next few cycles. If you want to get more aggressive, flush laundry detergent, add about a half tank of clean water and go sail. Pump it out when you return and then fill and pump fresh water once again. You should be close to where you started.

[PorFin]

Like others have said, I think you can rest easy at this point. Given the choice of mold or raw sewage, I'd suffer the mold any day and be happy.

The comment about not breaking out the biocide of your choice is spot on -- you NEED those microbes in the tank to break down the sewage. Slash and burn will work against you.

That said, does anyone else think that the mold growth may be attributable to poor ventilation? Tank ventilation is primarily designed to equalize pressure -- however, they all too frequently only meet this minimum level. Getting a good healthy flow of air in the tank promotes the growth of aerobic bacteria (which breaks sewage down) and retards the growth of anaerobic bacteria (which causes that godawful, makes you want to retch odor.)

[bubb2]

Change your diet!

[smackdaddy]

I think you need to post the pic....just to give Faster and Jeff_H higher BP.

In the mean time, stop taking pictures of your freakin' poo! I mean, WHO DOES THAT?