Had to go and check, and in the stickied thread for "How to do MTS"
it says this:
Step 9 – Top With Gravel
Cover the mud with more of the same border gravel from step 6. If you skipped step 6 then simply cover over the mud with the gravel of your choice. Cover the mud by about 1” in the front to 2” in the back of the tank to create a nice sloping substrate effect.
Now I didn't do a slope, but instead did 1-1/2 to 2 inch cap across the whole thing and I have been wondering if it's going to go anaerobic on me, as if stick something down into it here and there I get lots of bubbles ...
So are those directions wrong then???