The majority of organists don't spent too much time practicing organ playing. They play a few minutes here and few minutes there. In addition, they find it difficult to practice every day.
Sometimes such organists will complain that practicing organ playing is not for them. However, when I ask them how much time they spend on the organ bench, they respond by saying they play organ one day per week for 30 minutes with a total amount of 2 hours per month.
Of course, this is exactly why they keep on struggling. 30 minutes per week is just simply too little time to see any progress.
The more time you put in your practice the better. Some organists spend as many as 8 hours a day practicing their organ pieces. I don't recommend this approach. You see, if you play without a break for many hours, your practice quality most likely will deteriorate.
Instead, practice until you can keep you mind focused at the present measure. To train your mind, push yourself a bit further so you can extend your focus a few minutes longer.
With time you will find that your focus level improves and you can practice longer. So gradually you can extend your sessions until about 2 hours a day. I believe this is an optimum length. You still can make some rests every 30 minutes or so.
If you want to be the best in what you do, you cannot hope to achieve this level practicing only a few minutes a day. If you consistently practice 2 hours a day you will start noticing some tremendous changes and improvements in your organ playing very soon.
By the way, do you want to learn my special powerful techniques which help me to master any piece of organ music up to 10 times faster? If so, download my FREE Organ Practice Guide.
Or if you really want to learn to play any organ composition at sight fluently and without mistakes while working only 15 minutes a day, check out my systematic master course in Organ Sight-Reading.