Most cost effective and timely way to eliminate Fungust Gnats in small collection?

[itzi]

I currently have a few orchids growing inside, 7 to be exact. Recently while doing my morning inspection I noticed some little black insects flying around, and after taking a closer look through my phone camera, saw that they are fungus gnats. I've never had this problem before, so I did some reading here and on various sites and know of a few solutions; Bacteria strains, Ping plants, Mosquito dunks, etc. I just want to know which one of these would be affordable, fast, and not overkill for my small collection. I also will now be letting things dry out a little more... Thanks

My plants, for reference:

[Ray]

Insecticides, with maybe he exception of azadirachtin-containing formulations (NOT neem oil!) only kill adults and are quite pricey.

My suggestion is to purchase Mosquito Dunks or Mosquito Bits at your local hardware store, pu.t someone a gallon of water for a few days, then water your plants with it.

The active ingredient is Bacillus thuringiensis, which kills the eggs and larvae. Cheap, but may take a little while for full control.

[estación seca]

A fan blowing on your collection. You might already have one. You can read my previous messages on this topic to learn more. After about a week they are all gone. No poison in the house.

[Dimples]

I’m also a fan of mosquito dunks. Bt, the active ingredient, is a naturally occurring bacteria found almost everywhere and it’s safe for humans and pets. Does take a little while to eradicate them but it does work. Add the fan for a double punch.

[BobcatJohnson]

I, too, will suggest mosquito dunks as a cheap solution, however, as said, it won't eradicate an infestation quickly.

1) Break a single dunk in half, and place each half into 1 gallon jugs.

2) Fill the jugs with water that has been sitting for a few days for the chlorine to evaporate out of it. I don't know if this actually works or if it does anything at all but it works for me and if it ain't broke...

3) After the water has set for another few days it will have gotten infused with a good dose of B.T.I bacteria. Filter about three quarts of water out of the jug and make sure you replace the large pieces of dunk back into the jug, and refill the jug as in step two.

4) water you plants with the bacteria solution.

I do not believe the bacteria kills the eggs as mentioned above, it only kills the larva, it has to be ingested by the larva to be effective.

It will NOT kill any pupated larva, any pupa that is already formed in your pot will still emerge out an adult gnat.
This is why it takes time to be effective, pupas can take several days to emerge, once adult gnats are emerged they can live for a couple weeks, and the bacteria solution will do nothing to kill them.

Once the last of the pupas has emerged and the adults have died off, your infestation will be gone.

You can easily get a 6 pack of dunks for less than $10 U.S. and each dunk works for up to 30 days in a jug.

If you only use half a dunk at a time, and only use 1 jug to water, you can get twelve months of protection for the cost of 1 6 pack. 6 months if you use two jugs at a time with half a dunk per jug.

Lastly, as mentioned above, B.T.I (or some of its variants) is a naturally occurring bacteria that is found everywhere in the world. It is 100% harmless to all plants and animals EXCEPT the larva of certain insects to which it gives a fatal case of food poisoning.

[Dimples]

Leaving water out to offgass the chlorine in most places in the US doesn’t work anymore because municipal water supplies use chloramine. It won’t offgass and requires filtering (RO is typical) to be removed. Just pop the dunk in the water and wait a day. Keep it up until you aren’t seeing adults anymore, and for one week after.

[itzi]

Went to a local hardware store to get a 6 pack of mosquito dunks. Thanks yall! Sadly I dont have a fan but I've also seen some people put little chunks of potato on top of their medium in order to draw out the larvae, should I try that too?