Help with flies/gnats at my office

[Drewbacca]

I keep a 10 gallon cherry shrimp/pygmy cory aquarium at my office. I also have several houseplants. Last Spring I repotted the plants using an organic potting soil, and it came infested with fungus gnats. The office called an exterminator, who blamed it on my aquarium, which I've had in the office for 4 years without any issues with flies. I treated my plants and the soil and pretty much rid them of flies about 2 months ago, but now the office has tiny little gnats flying around everywhere again. They're not drain flies, which we've had in the past. Anyway, my partners are convinced it's my aquarium since the exterminator is convinced that's what it is. I don't see anything coming from it or my plants, but I don't want to discount it. I don't see any in my personal office, just in the common areas. There are cherry shrimp, trumpet snails, and pygmy corys in the aquarium. I may just have to move my 10 gallon home to combine with my 55 gallon if I can't satisfy them, but I'd hate to go through all that trouble if it's not the real cause. Any advice?

 

[Kribensis27]

Can you get a picture of the flies? Knowing the species (or at least family) would be helpful to find out if the aquarium is truly the source or not. What may have happened is fungus gnats just re-infested your soil, but it's hard to know without seeing what they are. Also, what kind of filter do you have? I've had some little gnat thingies live in my HOB filters before when I let detritus build up. These could also just be fruit flies lol. Pics of them are definitely needed.

BTW - what kind of houseplants, and how often do you water? Does anyone else there have houseplants?

 

[bumblinBee]

Does the tank have a fitted lid? If not, it may be worth getting one to eliminate the tank as the source.

In the event that these flies are indeed more fungus gnats, I'd suggest getting some of those sticky traps and/or make some vinegar-soap traps to lessen the volume of adults (or if you want to go the more interesting route, get yourself a butterwort). I'd also swap out the soil with some un-infested fresh soil to eliminate the majority of the larva (be sure to rinse your roots thoroughly when you do). One of the biggest culprits of fungus gnat infestations is over-watered plants, so try to reduce your watering frequency or even swap the plants you have to more drought-tolerant plants, maybe succulents or cacti.

 

[AP1]

I just got down outing a nest of ants from my light fixture. I ve see cockroaches make a home in lights/empty filter space before as well. Doesn’t seem likely, but any chance they are in the lights, hood, or dry parts of the filter?

 

[Philpig]

I keep a 10 gallon cherry shrimp/pygmy cory aquarium at my office. I also have several houseplants. Last Spring I repotted the plants using an organic potting soil, and it came infested with fungus gnats. The office called an exterminator, who blamed it on my aquarium, which I've had in the office for 4 years without any issues with flies. I treated my plants and the soil and pretty much rid them of flies about 2 months ago, but now the office has tiny little gnats flying around everywhere again. They're not drain flies, which we've had in the past. Anyway, my partners are convinced it's my aquarium since the exterminator is convinced that's what it is. I don't see anything coming from it or my plants, but I don't want to discount it. I don't see any in my personal office, just in the common areas. There are cherry shrimp, trumpet snails, and pygmy corys in the aquarium. I may just have to move my 10 gallon home to combine with my 55 gallon if I can't satisfy them, but I'd hate to go through all that trouble if it's not the real cause. Any advice?

The gnats come out of the potting soil. Then they lay eggs and you get another wave. Nothing to do with your aquarium at all.
What you can try is putting some sort of mulch ie shredded paper or wetted newspaper etc, to totally cover the pot soil for a while, until it breaks their cycle.
And tell those silly people that flying insects don’t live in / on aquariums!

 

[Drewbacca]

To tell you the truth, I haven’t seen the gnats, or whatever they are. I’ve spent the whole week watching my plants and aquarium and haven’t seen a single insect. Unfortunately, the exterminator saw my last fungus gnat infestation about two months ago and refuses to come back unless I move my aquarium out… even though it was obvious they came from my plants. I have a Guzmania, Burgundy Rubber Plant, Red Aglaonema, Song of India, and Peace Lily. It mostly started after reporting in the Spring, followed by my office manager overwatering everything while I was on vacation.

 

[Philpig]

To tell you the truth, I haven’t seen the gnats, or whatever they are. I’ve spent the whole week watching my plants and aquarium and haven’t seen a single insect. Unfortunately, the exterminator saw my last fungus gnat infestation about two months ago and refuses to come back unless I move my aquarium out… even though it was obvious they came from my plants. I have a Guzmania, Burgundy Rubber Plant, Red Aglaonema, Song of India, and Peace Lily. It mostly started after reporting in the Spring, followed by my office manager overwatering everything while I was on vacation.

Good riddance to the bad exterminator!

 

[coralbandit]

Mosquito bits for the win.
https://www.amazon.com/Mosquito-Quick-Kill-Biological-Control-mosquitos/dp/B003XS2572