Change AdSense ads size

Hi there,

I've got a website using AdSense for a while, and I made a transfer from Blogger to Wordpress.
Installed a theme and I put all my ads adaptable:
- Header
- After the main slider
- Sidebar (removed due to no clicks)
- Beginning of Article
- Middle of Article
- End of Article

Right now my problem is that I have an average CTR of 0,30% and 0,06? average CPC, and I want to increase revenue. I guess the problem is that in the best performers (Beginning of Article and Middle of Article) the ad size is a small banner. In Blogger the Beginning of Article ad was the best performer, and had a great CTR, with the 300x250 size.
The website is local targeted for a specific region for carnival. In December I was getting 100 average traffic (half of page views).
Started yesterday a Facebook Ad campaign to increase traffic until February, and right now I'm having at least 1000 visitors (also half of page views), not due to Facebook Ads but the content is more engaging due to carnival proximity.

I'd like to know if it's possible to change the AdSense code to have a certain size in each device (Desktop, Smartphones and Tablets). Any more tips are appreciated.

Thank you and Happy 2016 to all.

You should go and read up the ToS for adsense... you are not allowed to put that many ads on a single page. After removing the one i the sidebar, I still count 5 ads - if these are all bannerads: allowed are only 3!

Right! In the Homepage there are only 2 ads: Header and After the main Slider. I removed the Sidebar ad because it didn't have any click.
In the articles I got 4 ads: Header, Top of Article, Middle of Article and End of Article.
I checked the optimization tips of Google and I'm about to remove one. It will be the Middle of Article or the End of Article.
I'll change the positioning of the Top of Article ad also. The ad was centered before the article, right now I'll put within the article, on upper left.

EDIT: Do you recommend only text, only image or both?

nkt09 said:

EDIT: Do you recommend only text, only image or both?

Click to expand...

Really depends on your page but in general I'd recommend to keep everything activated because there will be more bids for the spaces to be filled.

Regarding your initial question about changing adsize's for mobile, you should have a mobile version of your website and detect what device the visitor uses to direct them to the appropriate version.
Here is a good tut how to do it:
http://stackoverflow.com/questions/3514784/what-is-the-best-way-to-detect-a-mobile-device-in-jquery

Yup. My theme is responsive, and after a quick search I found that I've got the "Auto" setting in all ad platforms.
Right now the question turns to which size should be the ads on tablets and phones.