depends
Twice a day
No, once per day is fine for Betta's.
Twice per day
NO B.I.D. means twice per day. Your doctor has requested you take you medicine twice a day.
One or twice per day.
The letter a?
Usually "per day" is abbreviated as "i.d", which comes from the Latin "in die". If you want to say twice per day, you would abbreviate it as b.i.d. (the b is for bi).
2 twice a day for each of them.
An equal day and night occurs twice per year on the summer and winter equinox.
they eat 2 or 3 meals a day
It is bis die (BD), a latin term meaning twice per day. It means you take the medication twice a day.Twice a day (also abbreviated: b.i.d.)
I recommend no more than once or twice per day and always with a full glass of water.