No...... I have always been told and read that untill you get around 40 there is no real problem. Nitrates at high levels can kill/stress the fish.
Only 1 fish?? When was the last time you did a water change.... Any skimmer, sump refugium?
I have a fuge, skimmer on my 55 fowlr
that is loaded with fish and it keeps it around 5, I do water changes about every 2 months.