+1 you are definitely pushing .5 ammonia if that test is accurately done.Perhaps my eyes betray me or the color is distorted, but your ammonia is not fine, it is not zero at all, when it should have been yellow, no greenish hue.
I hope it is just ammonia that's bothering it. Goonch require pristine, toxin-free water. Absolutely a must.
The redness you see may be the reaction to ammonia, not quite a burn but irritation.