I have 2 flagtails, 6" and a 4". I have both of them in a 240 gallon with 2 tiger Oscars(6" and 7"), jaguar(6"), 3 geos(2-4"), geo balzanii(4") and 6 tinfoil barbs(4-7"). They do well and my Oscars or jag doesn't bother them. I do have my tinfoils for dither to channel aggression. Both of my flagtails only mess with each other when eating. I will say it's hard to feed them cause both my Oscars and jaguar will eat there Hikari algae wafers. So I usually throw in a couple of wafers in when the lights are off. For the most part I love these fish. Keep my tank very clean.
I paid $90 for both of mine at 4-6". They are very pricey and very slow growers. I tried to grow out one in a 120 gallon with a jd, red texas/midas, jaguar. The flagtail was only 1" and it didn't last 2 weeks. I paid at a lfs $39 for a 1". Keep in mind these fish are seasonal from what my lfs said. I actually asked them last week if there are any in season. He said atm no. Good luck on getting your flagtail. They are beautiful.
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