what size arcadia should i get ??

[new_world_disor]

well my tank is 85cm accross. and is 65cm deep. i have just ordered an arcadia series 4 pendant. the 70cm 250w mh version. but looking at it the 55cm version is £200 cheaper. and ok i loose 7cm either end ( ish ) but will this really matter ?? will the 55cm be ok .. i want to grow sps mainly.

any input is appreciated(spp)

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