Moodle gives a white page and reports memory issues. Print

Set the following in your php.ini put this in the root of your Moodle installation - this is the only place you need it. You only need to put this in aphp.ini as php5 is now default on all of our servers. 

max_execution_time = 60 
upload_max_filesize = 12M 
post_max_size = 12M 
memory_limit = 256M 
display_errors = 0 

Next put the following in your .htaccess file in the root of your Moodle installation (create one if you don't have one already) 

SetEnv DEFAULT_PHP_VERSION 5 
php_value memory_limit 256M 
php_value realpath_cache_size = 128K 
php_value realpath_cache_ttl = 150 
RLimitMem 256000000 

The memory limit you require will vary, depending upon the size of your Moodle installation. Typically, you will not require such a large amount.