Nah, flagtail is all good, a really great fish for sure, active and colourful. Flagtails are retailing for about $109 from HFF, however this one has FAR superior colour than all the others that I have seen for sale, I think that 2 subspecies may have been imported, they were labelled as red tailed flagtail, and flagtail - growth rate has been great on mine, good diet and good tank conditions helped bring out colour.
I will probably be unable to upgrade lighting and add co2 at the moment, but what sort of fertiliser would be appropriate?