Odd white crap showing up inside aquarium glass? (Pics)

[ppo8820]

I have a brand new 29 gallon and an established 15 gallon column that is planted. BOTH tanks keeps getting these white, crust like patches that are hazy, hard to remove, and annoying inside the tank on the glass walls. I scrape them, but its hard to remove and seems to spread. Its driving me insane. I thought maybe it was something to do with the eco-complete substrate in both? (29 isnt planted.......yet). What is this stuff? I thought only hard water build up showed up on empty tanks or from evaporation? This is in side a full tank. Any help would be amazing!!!

 

[ppo8820]

You can see it starting in the new tank in the pics with the little angels. I hate this stuff. My water tests are all good, I have 0 ammonia, 0 nitrite, and about 10 Nitrates in each tank.

 

[Lung Fish]

I had the stuff once, above the surface of the water....