Still problems with the substrate soil

I was moving around the substrate soil in my Chilean Rose's tank last night, mixing it up, esp. moving around the soil underneath on the left side that still seems damp & I pushed over a bulk of the soil on the right side where the heating pad's located underneath & created a little mound in the middle. I also moved the heating lamp light towards the middle of the screen cover just a little to dry out the damp soil that still seems to exist. I then noticed that the humidity went up to 61% & the temp was 71 & gradually overnight, the temp went up a little & even as high as 77 at one point, but the humidity started dropping back into the high to low 50% range. I know you suggested for me to moisten a little substrate a little that I have left & mix it under the old substrate in there. Do you mean I should possibly soak one of the substrate soil bricks I have left in a bucket of water like I did 3 weeks ago while setting up my t's tank before getting him & just mixing the new soil in w/ the rest of the other soil, or should I go out & get a bag of echo earth & just mix it in w/ the other soil I'm using? Also, the other night, I noticed inside my tarantula's tank a very tiny white speck on the front of the glass inside & on another place on the glass in the back. I'm really hoping it's not some kind of fungus growth or mold even? It didn't come off right away, you'd have to either wipe it off, or scratch it off. And since I've been feeding my tarantula crickets at night, I've only removed 2 cricket carcasses from the soil & the rest of the times, I wasn't able to locate the cricket's carcasses anywhere after my tarantula's feasting on them.

With the bricks it is hard. It is probably easier to buy a smal bag of eco earth and mixing it under.
Did you try to cover the tank partialy to trap the moisture ? That helps most of the times.
Sounds like mold, the speck, wich is not so bad as long as you scrape it of. You should be fine, it happens.
Also if you dont find the waste balls thats ok, remove it if you find it, if not thats ok to. I cant find them, half the time, I just search for nothing. Dont know what they do with it