Hair algae like that isn't normal. I wouldn't experiment with cleaners, because that doesn't eliminate the problem. You have an abundance of nutrients, are you using tapwater? Also, some puffers have urchin's on their natural menus...they could end up being a snack like everything else even though you'd think the spines would be intimidating. IMO
, improving the water quality will go far in eliminating the hair algae while promoting better conditions for desirable algaes.
As far as lighting, you can upgrade the lighting without going to all out "reef lighting". PC
's are a nice enhancement, and should not bother the puffer. Some folks have said they grow coralline with NO
lighting, I have never been able to.