Hi, in my 36g tank I have a great blue gourami that I've owned for quite sometime and she shares a tank with 12 other fish and I try to feed for 13 mouths, my others don't feed directly from the top but the filter pushes flakes down for the others so that's not a problem. She stays right at the top literally sucking in flake after flake and she has gotten huge.
My brother has a large cichlid tank and a huge net, I've gotten the suggestion to put her in the net and hold her in the corner, in the water while the other fish eat but that seems mean, and I could see her freaking out and getting stressed if this happened every time.
My 20g QT is housing a betta and some neons and has for quite some time and my small 2.5g QT I fear would be much too small for a four inch fish. I know I could take her out temporarily but I watch her pick at the gravel for food and I've seen her suck a flake that was stuck in the filter intake..