Exactly how high is your temp getting? If its so hot it killed your fish then i would say ice or fans will not be enough. And ice really isnt feasible on a daily basis.
What lighting are you using? Also what isthe house temp. If your house is reaching 80 degrees + then its only making the problem worse. Keeping the house temp steady will help keep the tank temp steady.
I run a 150w metal halide on a 29g tank. With the house maintained under 76 F my tank temp will never climb above 79.0 degrees F. No fans, no chiller.
29g Mixed Reef, 150w 14k Phoenix MH w/ Moonlights, Reef Octopus BH1000 HOB Skimmer, Ecotech Vortech MP10es, ReefKeeper Lite (Plus), PH Probe, Temp Probe, ATO, Carbon/GFO Reactor.