If your plants are overwatered, fungus gnats can develop. Especially be careful not to overwater the aloe and the jade (hope it has a hole in the bottom of the jade pot). Also be sure the pothos does not sit in drain water in that outer pot. Your plants look nice though. Those gnats are annoying.

can i spray rubbing alcohol on the pothos?
it seems it works very well with jades but never tried it on pothos or aloe.

I know a lot of people who are using mosquito bits now to combat fungus gnat larvae. But I agree with above that you need to address the environment that is allowing them to thrive.

What are mosquito bits?

Biological mosquito control: you can buy Mosquito Doughnuts/Dunks or Mosquito Bits

They kill mosquito larvae because of BTI (bacillus thuringiensis israelensis) they contain. Dunks are good to put in water used for watering, bits could be sprinkled on top of soil (or water). They both work...Used to get rid of mosquitoes anywhere there is standing water (or damp soil which larvae live in and love). Safe for animals, insects, birds, fish and people. Better to use than synthetic toxins.

Mosquito dunks are better because you can crumble them into your watering can or cup. Good advice above!

L Evve

I would like to add, that soil in your photo looks quite wet. Either you water too often, or it is water-retaining. I do not know about pothos - I do not grow it - but succulents shouldn't be potted in water-retaining soil. I am saying it because it appears wet in photos, and also perlite (what I assume is perlite) looks yellow: that happens if it is wet for extended periods of time. If that is the case, environment is very good for fungus gnats.

And there should be drainage hole(s) in any container, as socks already mentioned.

I am only looking at your photos and comment on what I see. Photos could be sometimes misleading, and whitish-yellowish particles may not be perlite as I am assuming, so sorry if I am incorrect.

its perlite indeed. took the pics right after watering the plants... but i dont water them too often...

I, too, have struggled off-and-on with gnats thanks to our living situation; my partner and I rent an apartment with no screens on the windows and there are enough gaps and shared-vents for gnats to make their way into our unit from neighboring apartments. All it takes is someone next door leaving their fruit bowl too long, or opening a window after dusk, and we get gnats. I can't prevent them from coming in, but there are ways to keep them from sticking around. Here are a few tips I've found which have been invaluable for keeping my plants safe and infestation-free.

• Sterilize soil prior to planting by baking, steaming, or microwaving, even soil fresh from the packages. Commercial planting mixes generally contain peat moss and the bags are often left exposed to water; gnats can make their way into the packages, lay their eggs, and leave, and the peat can even be infested prior to mixing. Sterilizing the soil kills the eggs before they can hatch.
• Whenever possible, water from the bottom to reduce damp soil on the surface. Gnats are attracted to damp soil. I use nested window-box planters for most of my flowering plants - the top planter has drainage holes punched in it, while the bottom planter acts as a basin. The principle is basically the same as reverse-watering planters for African Violets, except I only add enough water at a time to get the plants by. You can also dig a hole in the soil, water, then bury the damp soil with dry, or after watering, disturb and loosen the damp soil so it dries faster. Another option is to deliver water below the surface by burying a plastic tube (like an empty pen barrel, or a piece of straw) and pouring water directly down that tube. Cover the mouth after watering to prevent any gnats from hitching a ride to root-town. I've gotten good results for my aloes with this one.
• Watering with Mosquito dunks never did any good for my plants; what helped was putting bits of them into drainage pans, water basins, and in the gravel in the bottom of planters. This slowly poisons the soil against any gnat larvae that hatch, and it doesn't hurt the plants.
• Gravel, sand, and dried sheet moss have all been suggested for keeping gnats from laying eggs on soil but in my experience, none are much of a deterrent. All three retain moisture beneath the cover and protect gnat larvae hatching on the surface. I've heard good things about a special variety of glass you put on the soil, but I can't recall the name.
• Yellow sticky traps are often suggested but can be surprisingly difficult to find in some cities. Fly tape, however, is generally easy to find. When I was fighting gnats in my basil a few years back, I strung fly tape between stakes in the planter; every time I watered, turned the fan on, or even just jostled the planter, gnats flew around and got stuck to the tape. Eventually, I found fewer and fewer on the tape, until the infestation was completely gone.
• Repot everything. This one can be pricey depending on the amount and variety of soil but it's the most useful. If a planter is infested, dig up the plant, toss out the dirt, rinse away the soil from the roots, and replant it in fresh sterilized soil, preferably better-draining soil. Give it a couple of days before watering again.
• Things that people swear by which either did nothing or made everything worse: Neem oil spray, insecticidal soap, scattering cinnamon on the soil, soapy water, soap suds, and burning incense in the planter. Don't bother.

Best of luck in eradicating the nasties!

If you have persistent fungus gnats, then you *ARE* absolutely overwatering or having inappropriate media.