Hmm i think 1.5 feet for height is good enough so theres an easy access for maintainence and so on. Refugium light i go with kessil as it say it can cover 2 by 2 feet and it has quite a good amount of power for algae to grow in the sump and outcompete with the algae in the main dt. Good idea about having a wavemaker in the coil compartment. May consider that if flow not strong enough. Thank you so much bro Im consulting iwarna Sent from Singapore Reef Club mobile app