Polypropylene fiber stuffing – Hydrophobic Filter

3-liter Polypropylene Stuffing/Filter Wool/Floss is a synthetic material used as a filter agent when constructing bulk grows and monotubs, or AirPort Jars.

This material filters and allows for gas exchange for bulk casing grows. It can also be used to make grain spawn jars for gas exchange – as will not clump/melt like polyester Poly-Fil.

Advantages:

• 100% Premium Propylene fiber
• Superior resiliency and smooth consistency
• Hydrophobic, and won’t absorb water
• Washable and non-allergenic
• Autoclavable and reusable

How To Make Grain Spawn Jars or ‘AirPort’ Jars:

1. Make a 5 mm hole in jar lid, a drill can be used carefully [watch out for hand holding lid.]
2. For metal lids advised to use a hole punch [support lid on piece of wood], drilling the thin metal of the lid will chew before it cuts, leaving a jagged edge.
3. For plastic lids advised to use a soldering iron to melt a neat hole, drilling the brittle plastic may form cracks – deeming lid useless.
4. Take some fiber and extrude it until its wispy, half a palmful should do.
5. Then fold it back on itself and back on itself again, do this until it is a wad of fiber not overly ‘tight’, and lay flat on hole.
6. Poke it through the hole with a pen until it is half outside the lid and half inside the lid.
7. If loose pull out and add some more and repeat from step 4 – until a tight fit is made with hole in lid.

How to make Grow Bag Filters – “Kenyan Filters”

The first I saw this was some document on oyster mushroom cultivation in Kenya [UNICEF?], but a useful cheap option to commercial Filter Patch bags. To make these bags you just need a polypropylene bag [or polyethylene layflat will do if not sterilizing substrate), 20 mm ring cut about 2-3 cm long, and Polyfil.

1. Fill bag with substrate – for layflat polytubing found that tapping on knee compressed nicely.
2. Gather bag and push through ring, in image the ring is cut from 50ml Polypropylene syringe – but found that normal black HDPE 20 mm irrigation pipe works too.
3. Pull bag through ring until ring fits snugly on substrate and fold over to open center of bag in ring.
4. Take a handful of polypropylene fiber and push in hole to make a snug fit.
5. If the substrate is to be sterilized, then wrap tinfoil over Kenyan filter to prevent water ingress during sterilization.

Microporous paper tape can also be used to affix fiber and help keep in place – especially with bulk grow Monotubs.

Packaged in 3# long bag.