Using specific input format for textarea

Anyone know how to use a specific input format for a textarea in form api?
There's no property for this option.

// This is my form element:
$form['easyco_custom']['easyco_custom_query'] = array(
'#type' => 'textarea',
'#title' => t(My Query'),
'#size' => 1000,
'#maxlength' => 1000,
'#prefix' => '',
'#suffix' => '',
);

I've created a new input_format using admin/settings/filters and I need to
use it here. It's a SQL syntax highlighter(it's not about executing this
sql, so no injection)

Thanks in advanced