product advice

I realized that I haven't been cleaning the tank properly, but was only concerned when my corydoras started dying off. I was doing water changes with cups (but I did add water conditioner). I would set a reminder to do it every two weeks. I want to get a siphon but I'm afraid I could...

Background: I just purchased this 5.5 gallon tank kit and began cycling today. I've used quick start, stress coat, and a bit of fish flakes. The filter, heater, and thermometer are installed, but only the filter is plugged in for now. I rinsed and added black sand, and the tank is filled...

I just ordered a 90 gallon tank with 30 gallon sumped tank below. This will be my first saltwater attempt. I am looking for suggestions on filters to use. I have only done freshwater and I know it is completely different so any product advice (or general advice) would be greatly appreciated...