Hello out there. I'm new here but have been in and out of fishkeeping most of my life. Currently I have a 35gallon hex tank, but my parrot cichlids have just about outgrown it. I have to to water partials every 2 weeks. I just got a 125gallon tank and am in the process of setting it up. I need some advice on some things: such as substrates, and I'm curious about all these elaborate filters in the DIY section that I've seen. Are they really necessary?
