I can see both sides of this..the pro and against use of an existing controller...but I would lean toward saying no to controllers unless they are detected form the budget. And while yes you are just using it as a glorified timer, it is a super expensive timer, a cadlights aquarium is just a glass box...but it cost much more than a glass box... that is my take on it...controllers and ATO's are ok if they come out of the budget. Just get a cheap timer and donate it to goodwill after the contest