I have a 5.5 barebottom tank with three pearl danios. I also have some anubias and my lights are on for 12 hours a day now. I do not have any algae problems, other than a couple splotches in the corners, and some light brown algae growth on my airline and its suction cups. Tank is in 70 to 78 range. Normally its pretty steady, however I know pearls like cooler temps and I will unplug my heater as the room is warm enough. I tested my water during my last WC (Saturday) and it was 0,0, then like 5-10 or so on nitrate. Now before I describe whats going on I need a slight disclaimer. I know I am right at stocking level, and a 5.5 is small for danios. When I bought the fish I needed something hardy that was not a betta, live bearer, and what I could find in a little college town. I cannot return these fish to the store, and rehome is not an option (unless family member starts up 29 again and wants them). I might get a bigger tank down the road but would only be a 10 gallon max as I have to move it every year. I am also a college student and don't have that much money to spend on fish. Sorry for being so blunt but had to get it out there. Now for the fish For the last couple of days one danio has been stressed and extremely skittish/easy to startle. Yesterday I came up to the tank (a little quickly) and he ballistic around the tank. Today the same happened but I kinda stomped on accident and shook the tank. That one makes sense on why he is skittish. Even slowly approaching the tank startles him. As I am sitting next to the tank now he is acting normal, although he seems to be at the bottom of the pecking order. I also put an old plastic plant from an old family members tank in there as cover and that kinda helps it seems (although it out of a 29 and looks huge in my 5.5). Pearl danio acting skittish, and colors are more faded than rest (stress sign)Solution A-Do nothing just watch itSolution B-Get another pearl danioSolution C-Get another decoration or thing for coverSolution D-Get live plant that grows well with stuff I haveSolution E-Fishlore suggestions Hope the bulleted list helps makes things clearer. Another thing I have noticed is that the pecking order has changed. The biggest fish (who I think is a female and has been bigger since day 1) is now alpha. The two smallest (who I think are males) are now second and third. The third guy is the one I have been talking about. Thanks in advance sorry for my harsh words at first.