2-3 inch dsb rock work redone

[mikenam]

So i redid my rock work and have a 2-3 inch deep sand bed. When i lifted up the rock all this black stuff came out. I did about 10-15% water change to clean up the water a little. When i see black stuff on the sand is that releasing nitrite, nitrate, or what ever in the water?



Thanks,

 

[smoothlarryhughes]

probably nitrates and could probably cause another mini cycle. I sometimes vacuum the sand and clean it out that way...anyone have thoughts on doing this?