Hello everyone! My name is Mike and I'm a 24 year old born again fish enthusiast. I just started up my own 20 gallon long freshwater tank recently. I've had tanks when I was younger but my father primarily took care of them so this is officially my first tank that I'm completely responsible for taking care of. I have a Tetra Whisper ex 30 filter and undergravel filter with a Tetra Whisper 40 air pump. I also have a 100 watt submersible heater in there. I did a fish less cycle and I just added two weather loaches this week. These were my favorite fish growing up because it was like "hide and go seek" when I was looking for those loaches lol. I have a couple questions. (Not sure if I should ask them in here or not but I'm going to anyway). I want to get more fish for the bottom of the tank. Particularly, yoyo loaches or julii cory cats. Maybe both? I wanted to know how many I could eventually have in my tank without overcrowding the bottom(or the tank in general). Also is it a bad idea to fill the bottom of the tank first before adding fish that swim on top? On to the next question. I'm having second thoughts on the ugf
especially after reading a lot of negative posts about them. Is it too late to get rid of it and the gravel? I want to put sand on the bottom. Sorry for coming out of the gate while most likely asking questions in the wrong place. Thanks for reading and thanks in advance for any advice.