Advertisement I've just finished mixing up a large batch of substrate with roughly a 30% peat moss component, and just read that peat acidifies the soil. Is this a problem? Its mixed with hardwood leaves/wood and coir in almost equal parts, with a slightly higher wood/leaf component, and a few handfuls of calcium mix. I'm planning on using this substrate for spirobolid millipedes. I know that pine and other conifers cause the soil to be acidic, and millipedes should not be exposed to resin bearing wood, but are they affected by the acidity alone, or by the insect deterrent compounds in the conifers? Or is it a combination of the two?