There's a lot of questions that I'd ask before changing anything Monty, is this your first season on the water or have you fished it before
If you've fished it before did you catch
If you caught why change
If you haven't fished it before then are you on the fish, you say it's a hard water but are you doing overnighters or long sessions, are you prebaiting or piling it in and sitting on it
If bream and tench like it then sooner or later a carp will pick it up, but you need to be fishing the right areas at the right times.
If it's a new venue then I'd suggest you use a bait that you have caught on before and are confident in, if it isn't a new venue and you are fishing areas that have produced in the past then I'd switch back to what you've caught on previously.
If you are trying to establish your bait then keep going, it's only a matter of time before a carp picks it up
More questions than answers and have probably not helped really
