已知数列\(\{a _{n} \}\)满足：\(a _{n} > 0\)，且\(a _{n} ^{2} =3a _{n+1} ^{2} -2a _{n+1} (n∈N ^{*} )\)，下列说法正确的是\((\:\:\:\:)\)
A. 若\(a_{1}= \dfrac {1}{2}\)，则\(a _{n} > a _{n+1}\)
B. 若\(a _{1} =2\)，则\(a_{n}\geqslant 1+( \dfrac {3}{7})^{n-1}\) C. \(a _{1} +a _{5} \leqslant 2a _{3}\) D. \(|a_{n+2}-a_{n+1}|\geqslant \dfrac { \sqrt {3}}{3}|a_{n+1}-a_{n}|\)
