XLS-A Horizon Unicorn Bag for Mushroom Substrate (up to 6.5kg)

We love these Horizon bags. Genuinely. They are absolutely magic. The XLS-A Horizon offers generous space and an extra wide Type A 0.5 micron filter patch, making them ideal for substrate blocks and fruiting bags that benefit from steady gas exchange without constant attention. Practical, reliable, and a quiet cheat code for growers who want results without babysitting.

• Size: 10″ x 5″ x 24″ (approx. 25 x 13 x 61 cm)
• Material: 3.0 mil autoclavable polypropylene
• Filter patch: Type A filter, 0.5 micron, approx. 2″ x 6″
• Ideal use: Substrate and fruiting blocks (not grain)
• Capacity: Up to 5 kg of CVG substrate, or around 6.5 kg of hardwood substrate, depending on density and moisture
• Filter placement: Higher Horizon position for improved gas exchange

Capacity varies with substrate. We use these bags for our 4.5 kg Masters Mix and hardwood substrate fruiting blocks, and the Horizon design handles the process confidently from sterilisation through colonisation and fruiting.

The extra wide 0.5 micron Horizon filter provides consistent, controlled gas exchange, which means fewer interventions and less risk of over drying or over saturating. We also use these bags in our no mist, no fan humidity tents, where the filter patch manages gas exchange without the need for spraying or fanning. Ideal for low maintenance fruiting and simplified grow kit setups.

If you're looking for a smaller bag for your mushroom substrate that can handle up to 3kg, Unicorn 14A is the one to go for.