Water quality

Hey im new at this stuff and ive been having a few issues lately. Just wondering my Amm 0, Nitrite 0, I keep my ph maintained to 8.2-with a buffer. Just wondering about my nitrate, im trying to get it to 0 but the best I seem to be able to do is 10-20 ppm, is this alright? The tank has been set up for approx a year. Im battling ich in a regal tang right now and trying to get the water the best I can, And using polyplab medic which I stopped for a couple of days after losing my powder tang but started using again today to try to cure the regal.

 

Is your tank a FO, FOWLR or a Reef? NA at 10-20ppm is ok, my tank is a 55g reef and I can't get my NA under about 10ppm but all is well. I just do my normal water changes and watch params. I am slightly overstocked so that is most likely the reason for my NA readings.

What is your tank size, fish load, filtration?

Do you know your extended params: Calcium, Magnesium, Alkalinity, Phosphate? If you have a reef tank, those params will greatly play into the overall health of the tank. I have no exp using polyplab medic, I have had a Blue Hippo for 6 months, never had an ich issue luckily. What are you buffering your PH with. IMO a steady PH is the best way to go, even if it's a bit lower/higher than what you want.

 

Mine is FO with a couple anemones , 50 Gallon tank with a basic filtering system, 30-60 aqua-tech and a marine land with a single bio wheel and a couple of pumps for circulation. I do not know what the params are. I am buffering with a reef buffer ( seachem is the brand ). Sorry for not sounding very knowledgeable, I just purchased the tank with most of the fish already in it recently within the last month or so , so I am still learning alot of the basics.Ive had a powder tang and a mandarin goby die in this tank in the last four days ( both fish I introduced to the tank, they both lasted about a week each )