Zonon 256 Pieces Synthetic Filter Paper Stickers 20 mm 0.3 ?m Synthetic Filter Disc Tape Mushroom Applied Under Wide Mouth Mason Jar for Mushroom Cultivation

Great product does what it is supposed to do

Drill two 1/4 inch holes. Insert a self-healing injection port and put one of these on the other hole. Use for liquid culture or spawn jars to allow for air exchange. I've only gotten to use them once but they held up to pressure cooking for 90 minutes to sterilize.

If you need these for liquid culture/grain jars they work just fine. They stick well and handle autoclave as intended.

I put these on mason jars for mycology projects. Used to get contamination all the time before I started using these. Now I can't live without these

I like the filters

I’ve had a few runs with these filters and have had great results. No issues with outside contam not anything relating to thier adhesive powder. My gourmet game is being changed!

I have used AND REUSED these filters on well over a 1000 different jars of spawn. From WBS, to Corn, to Oats I have had and maintained tremendous success using them. Any contam’s I can only equate to my own doing. Because like I said I’ve used & reused these filters multiple times w/ no issues. If your spawn has somehow been contaminated. I would definitely change it out before the next use.I would recommend using plastic lids since they won’t rust from multiple uses. I also recommend using a 1/4” drill bit for your Gas Exchange (GE) hole. As this seems to be the perfect size and best fit for these filters!I HAVE ONLY EVER NEEDED TO PUT 1-FILTER ON EACH JAR! Ive seen ppl say to use multiple but IMO I do not feel it’s necessary. I place on top on the outside of every jar. That goes for both regular & wide mouth lids.

I've used these on my last two grain runs, haven't lost a jar to contam yet! No problems with them coming off in the PC at all. I don't remember what I paid for them, but they were worth it! Now I'm passing them along to grow members of my mycology community for them to try too!