Welcome to the board!
This system isn't such a bad thing (I like it better than DIY bottles), but you'd do better with 2 of them on a tank of that size.
It's not uncommon for it to burp the bubbles half way up at first, but if it keeps doing it for a few days it needs to be checked for correct positioning of the tube, or other obstructions in the way (my Oto's did it).
Running it at night is probably fine unless you have a very low KH. I don't know how you would stop it at night anyway. :???:
This system isn't such a bad thing (I like it better than DIY bottles), but you'd do better with 2 of them on a tank of that size.
It's not uncommon for it to burp the bubbles half way up at first, but if it keeps doing it for a few days it needs to be checked for correct positioning of the tube, or other obstructions in the way (my Oto's did it).
Running it at night is probably fine unless you have a very low KH. I don't know how you would stop it at night anyway. :???: