high nitrates ?
normal process is things break down into ammonia (decomposion & rot)
PH may convert ammonia into ammonium (under 6.5 it's almost all ammonium, and untestable)
ammonia is converted to nitrite
nitrite is converted to nitrate
plants can take in (in order of preference) ammonium, nitrate, ... then they have to work hard to take in anything else.
do you have plants ?
plants apparently are happy at about 40
(i don't care about most test kits so i'm going on what i've heard)
a little more important, ... are your nitrates really at 80 ?,
check your lighting.
doublecheck your kit,
-it would really suck to find your nitrate test kit is thrown off by the color of your lights as you measure
as for ammonium, ... that's a fun one, ... our test kits don't test for ammonium, and it freely changes back and forth between ammonia & ammonium, your only ever going to read a percentage of the tanks ammonia/ammonium in the tank, again, less than ph 6.5, your % will read zero no matter how much much ammonium is in the water, ... a PH change then is the scariest thing in the world.
it isn't till about a PH of 9.5 that things are 50/50, ... not realistic for any tank
ammonium on the other hand, ...
bacteria is required to break down ammonia to nitrites to follow that direction on the simplified nitrogen cycle
the simplified nitrogen cycle doesn't include ammonium
and one kind of bacteria can convert nitrites to nitrates, and another kind of bacteria could convert it to ammonia (an option in the world of possiblities), ... as well as having various other amounts of many different Nitrogen compounds, (Nitrous Oxide, N2O, Laughing gas - same chemical) may not be realistic to have happening in our tanks, but in the world of possibilities, welcome to what really happens in the processing of nitrogen by bacterial activity, ... well only half the cycle, ... because there are other bacteria that will take N2 and without anything breaking down, start the nitrogen cycle
so far i've only head of cyanobacteria,
i don't know what medications you used for your ick, ...
for myself, never again, i will never use medications for ick, ... they're not effective, they're toxic and dangerous.
i add some salt, raise the temperature, ... the raised temperature increases the ick metabolism, the raised salt kills the ick when it's sensitive to it
medications can be either strictly toxic (in the hope of killing the disease before it kills what is valued
or they can be gram positive or gram negative, ... and these work by killing one type of infection OR the other, ... think anti-biotics & pro-biotics.
now, ... do you know what's happening in your tank ?