Yes Just check underneath bogwood and heavy objects regularly. It can even turn pitch black and won't come out with rinsing.Is this the effect of some anarobic do daddy ?
sand is a popular choice for many desplays but it can compact and stagnate over time,turning black and releasing toxins.plant roots will help to stop this happening,but in open areas you will need to agitate the sand gently with your fingers once or twice a week.Heating cables placed beneath a sandy substrate can help and keep the are oxygenated.
i plan to add malasian trumpet snails after the cycle. and about a dozen or so corys.
I was planning to plant some java fern on this bogwood, would having to move the wood every week to stir the sand harm the growth of the plant? or if i also added some amazon swords and other root feeding plants around the wood (as aparently plants thrive with anarobic conditions) would that counteract it?