While you are managing your blog, you might have special attention on your blog's look and feel. Arranging page elements, widgets and customizing template are common design practices in many bloggers to impress their blog visitors. You may have seen an empty white space below Blogger comment form. Mostly it doesn't matter if you are selected not to display backlinks for your posts. If you have enabled backlinks in your blog, it might be troublesome on the aspect of appearance of your blog by occurring much white space gap below comment form. The reason for this gap is the height of your comment form area and you can alter this on your Blogger template. Wanna know how?
Before You Go:
This workaround is only applicable for standard Blogger comment form. If you are using Google+ comments or other 3rd party comment system, the same workaround won't work.
1. Go to Blogger Dashboard.
2. Click on your Blog Title.
3. Navigate to Template from left pane.
Note: Before editing your template, you may want to save a copy of it. Read How to Back Up Your Template.
4. Click on Edit HTML button.
5. Find the below code in your template.
<a expr:href='data:post.commentFormIframeSrc' id='comment-editor-src'/>
Note: You will find 2 results for your search in different places in your template. Select the second search result and apply next steps.
6. Find the immediate line next to the code you have found in above step.
7. In iframe tag you can find the attribute height. Use lower value for height attribute to reduce the height of comment form - i.e: height='250'
8. After changing height value, save your template and preview your blog. If the height feels uncomfortable, try another value for height attribute.