Wonderful kbod, you're clearly got the hang of it now and your tank sounds much better!
Glad you downsized and got a better fit for the gravel-vac. Establishing good gravel-vac habits is core to keeping a good healthy tank!
Yes, its great to take rocks and ornaments out to clean if you want, makes it much easier. No need to do it every time, but when you are not so rushed then it should be done. I'd just get an old toothbrush and make sure you rinse the heck out of it so there's no old stuff on it and use that to clean off the algae, which is probably what those spots are. Algae comes in browns and blacks as well as greens! Things in tanks feel slippery because there are "biofilms" grown by the bacteria on every surface eventually. That's normal and harmless.
Yes, the tank gets extremely cloudy and dirty when you gravel-vac. That's quite normal in an established tank with fish and/or plants. Your filter will clear it up after a while.
We try to help beginners establish good maintenance habits by gravel-vaccing at any water change, but if you're having to do two a day, then nobody's going to fault you for not doing it both times. On the other hand, I find I want to control the gravel cleaning cylinder and not let any of my fish get in it, which makes it pretty easy to at least lightly gravel-clean while I'm holding the thing, just to keep busy.
~~waterdrop~~
Yeah, hop the next transatlantic and get some filter muck, lol. The irony is I do actually happen to have an extra empty house at the mo!
