White powder in pool, need advice for fixing.

[swimswimswim]

I have a new theory as to where the powder may be getting through. http://imgur.com/iHiljXM part number 10, 14, and 4 in that picture. It seems the tube was not well attached at 14. Could the powder be going through there? Also, part number 4 is a small filter, but the holes in it are very large, and powder could definitely pass through that thing unless maybe gravity keeps all the powder at the bottom of the tank? I'm pretty sure there's not supposed to be air at the top of the tank where 4 is located. My parents told me that you are supposed to let all the air out through the top until water comes out.

Also, how does the seal between part 15 and the pipe leading back to the pool work? It looks like part 15 just rests on top of the pipe. Couldn't powder escape through there? Here is a pic of that pipe http://imgur.com/wp3Y5qb
Here's a pic of the grids http://imgur.com/ou9JevO
The system is "Anthony Pools Apollo VA-52 DE Filter". Here are more pics: http://imgur.com/a/3sp6J