Here are some suggestions for your set up to prevent your tank from crashing again.
1. Raise your return nozzle to your water level to create surface agitation to aerate your tank.
2. Get a power head about 800 gph
installed midway at the right side of your tank for water circulation.
3. Turn down your light since you do not have any corals yet or still cycling. All you need for now is just enough light for your fish to see what they eat.
4. You need a surface skimmer to remove any floating debris or oily substance or you can just manually remove them.
A smelly water means you need some carbon media.