Is it bad to keep my fish tank full?

Yeah i keep mine full too it does look better. i dont think that its unsafe to keep it full, but the people who keep theres low may just like it that way and possibly do it to keep their fish from either jumping out or into their filter or something.

But ur fine to keep it full, i always have. There built to be filled all the way.

The fish wont jump if there is a lid or hood. and it also depends on the fish that are in the tank.

Just keep the top covered and ur fine.

No its not as long as you take certain precautions. The 1 inch per gallon rule is really extreme. I had a friend when I was in school who had 100 fish in a 10 gallon tank. He had a really good filter, didn't overfeed, and they were small fish. His tank looked like Grand Central Central though. While I would not recommend doing that, with over 40 years of experience, I have often kept 1 1/2 as many fish in a tank as the golden rule allows. You really only have to make 2 adjustments: get a power filter which is one size too large for your tank, and change 1/4 of the water every 2 weeks

For instance I rountinely keep 8 six inch fish in a thirty gallon tank with a 50 gallon filter . I keep species that like to swim like Viejas and Wolf Cichlids on top, and Catfish , lungish, and Geophagus on the bottom. Thus the tank doesn't look overcrowded, just busy. Even with nasty Flowerhorns, put one of their juvenile spawn in with them, and they accept them even if they haven't seen them for 6 months. Thus I double the amount of fish in the tank

As long as there's a little bit of air between the top of the water and the tank lid, you're fine. It doesn't take much air space-- maybe a quarter of an inch (because the top is not air tight, so there is some air exchange).

Of course, if you fill it to the top with no cover on the tank, the fish are likely to jump out. But they can jump out of uncovered tanks with lower water levels, too.

yes cause my fish jumped out and we didnt notice until a day later so don't do that ok