I assume you are talking about the file in the ow_log folder.

Turning off error.log is not a good idea.  Just edit the file from cpanel and empty the contents, (select all del) then save.  Or you can just delete the file entirely and create a new one error.log  text file.   I also believe if its not there oxwall will create it.  

Then you need to edit it once in a whiile to keep it cleaned out, there is no reason to look at errors that occured months ago.  Just clean it out every few weeks and your good to go.  

Also do the same if there is a error log file in the root of the domain that the server creates, if its not in public_html or your domain folder then all is good and you dont have one.  If you ever see one look at it... 

The problem with letting log files get too big is that they get to the point that we cant load them because they are so huge. 

OR better yet, fix the issues.   Now remember that "notices" are not fatal, most of them are due to improper coding practice from the dev but they are not fatal they are just what they say they are "notices". 

Open ow_includes/config.php and add somewhere a new line:

define('OW_ERROR_LOG_ENABLE', 0);

This disable also the cron_log

Again it is not advisable to disable the log.  Owning a site has certain repsonsibilities including regular maintainance duties.   I advise you to fix any issues in the log and move on rather than disable it..   But that is up to you....  good luck... :)

Thanks dave for the support. I have got to go over my code and make it cleaner case there are tons of empty and not declared variables all that gets picked up by the error log. Do you think this log can impact the site load time?

No i dont think it will effect that enough to matter if its just notices.  Is this error log file in the ow_log folder or the public_html

Amazing thanks Dave and Paul