Does anyone know the minimum temperature + length to kill fungus gnat eggs in soil?

[chimei]

I have had bti (and everything else I tried) resistant fungus gnat infestations in the past.

I have started cooking my soil with heat before using to help avoid this again.

I had read that a minimum of around 150 degrees Fahrenheit for 30 minutes should kill off any fungus gnat eggs and other pests.

Anyone know if similar to sous vide for cooking meat with lower temps x longer time to kill off bad things, if it is possible to cook soil at a lower temp for just a longer period to kill off fungus gnat eggs?

I have found the soil baking at 130 gives off allot less odor and I assume creates much less risk of any creation of toxic gas then higher temps. I cannot for the life of me find any articles on the minimum temp that is required to kill fungus gnat eggs. If I can do 130 for 2 hours instead of 150 for 30 minutes it would be allot easier. Getting up to temp is allot quicker at 130 too.

Thanks

 

[mr underhill]

taking a trip down google lane using the key words *sterilizing soil with heat* will yield a few different methods.
Personally I cook my soilless mix or coco coir in the oven
I wet it first using reverse osmosis or bottled water, no ph adjustment/addatives
put it in a big turkey pan so it is 3 to 5 inches deep and cover it in aluminum foil.
preheat the oven to 200F
use a meat thermometer thru the tinfoil to measure heat after 30minutes.
As soon as the soil reads 180F on the meat thermometer, shut the oven off and leave the soil in the oven to cool for a couple hours.
That will kill everything, microbes included.
Important to note though that this will kill any organic soil as well so is reserved for soilless mix and coco coir. I often find insect outbreaks after introducing fresh bags of media to my grow so sterilizing first is a smart step I think.
I also sterilize my cloning and seedling media as well and am very anal about that.

**do not over cook the process. Make sure to monitor the soil temp closely and shut that oven off when the soil temp hits 180F in the middle.

 

[Dropped Cat]

I boil my coco/soil 100C/212F for 5-7 minutes, then let stand for twenty minutes.

Add back bennies to soil, and you good to go.

 

[chimei]

Thanks for the responses. Yes I did google baking soil and most said it takes the soil being at 150 for at least 30 minutes to kill anything. (I am mainly concerned with fungus gnat eggs) I have a 20 quart stock pot I have been using. Unfortunately even with the lid on it, it takes a long time at 225 just to get up to 140. It took like 4 hours. I am guessing because of the total volume of the pot. I use one of those cooking thermometers with the wire with the probe submerged 95% of the way in the center of the pot with dirt. (with the lid on, and the wire coming out of the edge) I water log the dirt so it is a better conductor of the heat.

It dawned on me during that time that it being at 130 for almost 2 hours, that there is a possibility that lower temps for longer time periods are just as effective at killing the things in the dirt as food for example. Like cooking food, you can cook ground beef patties for 2 hours at 133 and it is as good as pasteurized. No need to get the meat up to 160. Because of the length of time at the temp.