First monotub — no pins after 14 days, what am I missing?
52 replies · Cultivation
Set up my first 112qt monotub two weeks ago using CVG substrate and GT grain spawn (10% spawn rate). Followed a standard Martha setup — 90–95% RH, 74°F, FAE every 2 hours for 30 seconds. Mycelium colonised the substrate in about 9 days and it's been sitting fully white for 5 days now with zero pinning. I've done two dunk and rolls on the casing layer but still nothing.
Conditions: RH 92%, temp 73°F, lights on 12/12. I'm getting frustrated — the mycelium looks healthy, no contamination, good white rhizomorphic growth. What am I missing?
Spawn rate is almost certainly your issue. 10% is too low for bulk grows — you want 20–30% minimum, ideally closer to 1:2 or 1:3 grain to substrate by volume. Low spawn rate means slow colonisation and weak primordia pressure. Also 73°F is a bit warm for pinning — try dropping to 68–70°F.
Are you seeing any consolidation or yellowing on the surface? That's normal pre-pin behaviour. Also, have you tried a cold shock? Drop temps to 65°F for 24 hours — sometimes that's enough to trigger a first flush.
What's your FAE setup? 30 seconds every 2 hours is often not enough for a 112qt tub. I run 4 whip holes + passive top holes and let CO2 dissipate naturally. Elevated CO2 (from too-tight FAE) will suppress pinning even with perfect everything else.
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