How flat is flat, and have I messed up?

[ben3290485]

I have a small downstairs toilet which I am tiling. It's only 1.78m long by 0.8m wide. Where the toilet was there is a small bump in the floor. I am laying 45x45cm so 8 tiles will cover the whole floor. On the right half of the floor the floor is flat, but around the old toilet area if I put a spirit level on the top, I've probably got 2 to 3mm on each end of the spirit level. I am using a trowel with 10mm x 20mm notches in it.

Will the flexible adhesive and a spirit level flatten this off, or do I need a self levelling compound? And if I do need a self levelling compound, do I do the entire floor?

Lastly, where I took up the carpet grippers and toilet there were some small holes. I filled this with polyfilla.

Is this polyfilla going to cause me problems, or will it be fine once I put the primer, (possible self leveller) and flexible adhesive?

Any help really really appreciated!

 

[Keithmac]

You can take 3mm up with the adhesive, can you lay the highest tile first and work from there?.