Huge issue with fungus gnats in my composting toilet. Ugh. Please help!

I've been using a composting toilet for about 5 months and for the last 4 I've been in a constant battle with what I believe are fungus gnats. Other than that my composting experience has be absolutely perfect. I'm using a Nature's Head with lightly damp peat moss. The problem is, every time I dump and refill the toilet, within a matter of days, the fungus gnats are swarming inside the main chamber. I'm doing everything the manual told me to do, the ventilation fan is working fine, I churn it after each use, etc. I've tried varying levels of moisture in the peat moss, damp enough that white mold grew all the way up to nearly dry. No matter what the gnats congregate and reproduce in the toilet. They're getting out into my house, which is obviously very unsettling considering they're in my toilet.. They've become my nemesis. I've gotten to the point where I just take the seat off and leave the toilet outside until I bring it in to use it.

Someone please tell me I'm not the only one with this issue. I've looked online, can't find much about gnats which is compost specific. I keep my house clean, I leave little cups of apple cider vinegar/drop of dish soap all over which does attract and kill them, but never solves the root problem which is the toilet. I'm willing to try anything at this point, I'll even resort to spraying chemicals in the toilet if that's what it takes (so long as it doesn't cause the compost to smell). If nothing else I'm hoping that this winter I'll be able to eliminate them, and somehow keep them away next spring/summer. But this has been so frustrating and I'm at a lost.

You're certainly not the only one to struggle with such critters in your composting toilet. We have struggled with what I believe are fruit flies in ours, despite many efforts to exclude and eliminate them. You're right, it's definitely unsettling.
From reading about fungus gnats, it sounds like when growing plants, they can be an indicator of overwatering and that allowing the soil to dry can serve to reduce their numbers greatly. Adding a layer of sand, mulch or diatomaceous earth was also suggested.
I know something we have found helpful, although not a total solution, is more frequent emptying of our toilet chamber (bucket, in our case). Every few days, or maybe even daily, so as to interrupt their reproductive cycle and reduce the numbers.

I have a suspicion (confirmed in the article below) that the peat moss may be a carrier for fungus gnats. Whether it's the source or not, it probably does encourage them. Especially since it is damp. Could you perhaps use a different cover material and see if that helps? This article has some suggestions for natural ways to eliminate fungus gnats. Hope you find a solution! https://yourindoorherbs.com/get-rid-of-fungus-gnats-soil-home/

Heather Olivia wrote:You're certainly not the only one to struggle with such critters in your composting toilet. We have struggled with what I believe are fruit flies in ours, despite many efforts to exclude and eliminate them. You're right, it's definitely unsettling.
From reading about fungus gnats, it sounds like when growing plants, they can be an indicator of overwatering and that allowing the soil to dry can serve to reduce their numbers greatly. Adding a layer of sand, mulch or diatomaceous earth was also suggested.
I know something we have found helpful, although not a total solution, is more frequent emptying of our toilet chamber (bucket, in our case). Every few days, or maybe even daily, so as to interrupt their reproductive cycle and reduce the numbers.

I have a suspicion (confirmed in the article below) that the peat moss may be a carrier for fungus gnats. Whether it's the source or not, it probably does encourage them. Especially since it is damp. Could you perhaps use a different cover material and see if that helps? This article has some suggestions for natural ways to eliminate fungus gnats. Hope you find a solution! https://yourindoorherbs.com/get-rid-of-fungus-gnats-soil-home/

Thank you SO much, that article was golden. What I did was change the peat moss, and when I moisturized it I added probably like 4-5 teaspoons of Dr. Bronners soap to the water and mixed it in. It's been two weeks now and no more fungus gnats! I haven't seen one in over a week, as far as I can tell they're gone from my house. I'm so happy. And so far the soap hasn't disrupted the composting process from what I can tell.

Thank you SO much, that article was golden. What I did was change the peat moss, and when I moisturized it I added probably like 4-5 teaspoons of Dr. Bronners soap to the water and mixed it in. It's been two weeks now and no more fungus gnats! I haven't seen one in over a week, as far as I can tell they're gone from my house. I'm so happy. And so far the soap hasn't disrupted the composting process from what I can tell.  

You're welcome! Glad to hear it worked. That's such a relief to be free of them and the unsettling feelings that go along with their presence!

I use shavings alot of times I buy them from tractor supply but I have a fungus knat problem. I spray with vinegar water everything I finish using the toilet(bucket).

I have a Separett. No peat or shavings or anything. I have no house plants. Per blower-door test my house is essentially air tight except for Lunos ventilation system and the Separett exhaust fan. I clean all air filters regularly. I get no bugs in my house - no flys, spiders, etc. Yes, essentially air tight. EXCEPT  I get fungus gnats in my toilet, usually mid-late summer. Any idea where they might come from? Spontaneous generation? I poop them out?

I hate this naturehead toilet. It's nasty. The gnat eggs get under the seat. In the parts I can't get to to scrub out. I'm about to lose my mind with this toilet. I have gnats in my house. Toilet gnats. It's disgusting. Help. Ive done everything I know.

I have had success dealing with different gnats and eggs by using a spray bottle of isopropyl alcohol to clean my bucket system components if I discover any activity. I do not dilute it when I fill the spray bottle but I imagine you could.

Hi Tera. It's a pity you're having problems.
I have been using a simple dry toilet and there aren't any critters ever.

My guess is that it's too moist in your dry toilet.
Can you locate whether thy're coming from the urine part or the other one?
How often do you empty it?
What do you use as substrate?
Could you switch to a simple bucket for a while and see if it happens there too?

I use wood chips for daily cover in an outside-the-house latrine.   If its cold or rainy, I have a wood chip lined bin that I can use inside (1 time and empty right away).  So, that's how I keep the bugs outside ...keep the #2's outside as soon as possible.

The Humanure Handbook is an amazingly useful reference book for composting toilets, even if you are not using its bucket system.

The book recommends using sawdust that has been left to be damp and weather for at least a few months. Rougher things like wood chips or shavings leave gaps between them that small flies can climb through, whereas sawdust makes a tighter layer, but is still light and quickly decomposed.

I mix coffee grounds from a cafe with sacks of dry sawdust and water the sacks till damp. They heat up within a day, stay warm for a couple weeks, and then cool down. The resulting cover materials is a silvery grey weathered wood colored sawdust, pleasant smelling. Good stuff.

If peat moss is giving you flies, try fine sawdust. If it's too dry it rolls off and doesn't make a good seal, so it's better to have it predampened and preweathered.

Thanks for the tips, Rebecca.

We have just "commissioned" the used Sun-Mar Excel which we bought from friends at church - 20 years old, if a day, but still functional (and fairly lightly used, just until they got a drain field installed).  This is in part of a storage shed on skids which I mostly built last year, but am still finishing.  It will serve as the main sanitary facility at our lake lot, with the black water tank/toilet in the camper trailer for middle of the night or viciously inclement weather necessities.  So far, so good, but the Labor Day holiday weekend was the first big test (with guests, no less!).

I have end-of-summer left over peat moss from a local hardware store's garden center (it was snowing - just flurries in the air - in a neighboring community just this morning, so the end of the season is fast approaching).  I got some wood shavings from Tractor Supply, but will try the local one-man sawmill and outdoor furniture manufacturer for sawdust or planer shavings.  My brother had some sawdust from running his band mill, but it all got used as mulch/path cover for the greenhouse operation he bought this spring, so I will need to resort to another source, at least until I make some appreciable amount of sawdust of my own.  The advantage of the bagged stuff is that it is dry-ish, so less likely to freeze this winter, though I do have a scheme to (hopefully) keep the temperature of the toilet room above freezing during sunny weather, at least.

As I said, no problems with the Sun-Mar yet, but it's still too early for a proper assessment, so any helpful tips are great.