Hi bro Bluezing, red star i bought at Coral farm at ard $12 if i remember correctly.
Thanks bro Jasment for your info . came to think back, i regret getting 2.5" height. really got problem for maintenance . still have to climb on top of a ladder inorder to stretch my hand to the bottom of the tank. so , often i have problem in placing any corals below. and upon getting a T5 light as compare to MH, it might not be able to penetrate deep below. so no choice have to shift up the corals. consider MH, incurred high electricity bills..luckily i decided to go bare bottom. so all debtrius is more easy to be filter out by a battary operate pump. i realish less problem for bare bottom tank . And also more coraline aglae( purple, bright pink type) grow all over my tank since i set up till now. never use any CR . thinking of getting on CR. but not sure how to set up the CO2 and the system to tune.