Ohhhh, Lawd..... first off Hi donnabright2002!
Ok everyone. Look. IF the tank is cycled, and well, the tank ammonia is lower than the tap water, and nitrates are coming up in the tank, so, yeah it's cycled.
Whole lot of back and forth here on what to do about this situation, And Honestly I keep coming back and thinking "is there even a situation here that needs addressing, or some store worker that doesn't know whats going on due to inexperience, giving advice, and scaring someone into going overboard trying to fix an issue that isn't creating any problem""....
IF the temp is 78F or
cooler, and the pH is 8.0 or lower and doesn't continue to go up,
It's likely not going to have any adverse effect whether it's 0.50 ammonia, or 3.0 ammonia or anywhere in between.
We all have seen the API master test kit chart and the problems people have figuring out the colors and doing the testing process with the vials, bottles of liquids and big vs. small holes hard squueze vs. soft squeeze, it's about as accurate as
test strips in reality, and in reality test strips are as accurate as the API master kit. it makes no difference, NEITHER is completely accurate and prone to errors or mishandling or misreading of the color charts. whatever you are comfortable with is good enough t get the general idea of how the aquarium is doing. Cheap knock off test strips should be avoided though.
The MOST IMPORTANT THING is that the aquarium is in fact cycled. if ammonia is going to nitrates, you don't need to test nitrites, nitrites are converting if theres nitrates. if the cycle is weak or transitioning you can get a backlog of ammonia or nitrites also, but that passes with time. Nitrites aren't particularly toxic anyways and takes like 5ppm to get in the dangerous zone, but I've been higher with minimal stress and no deaths. So it's not a hard rule. Ammonia and Nitrites should be "0" in a perfect world, but things aren't always perfect.
Water changes should be done regularly, you'd want to water change 100% of the water in the tank 1x a month and do it over a few water changes. if you tap water has ammonia in it, you'd need to do smaller water changes more often, say 25% weekly so that 5 gallons of new water with ammonia gets diluted by the 15 gallons of water without it that the tank has already taken care of, making it even more safe for the fish.
First post on this is Nov.18th , it's Dec. 6th. If all fish are still alive, eating and not acting strange/stressed and still looking good and healthy, then CLEARLY if it's a problem, it doesn't need outside influence to solve, it's mostly been sorting itself out just fine for the last 18 days.
As far as I can tell in this thread, no fish has died, everyone is fine, some fish store tested the water and freaked, but hey, like I said, not everyone is a genius and knows how to operate the tests at a store, and you shouldn't trust other people with your water testing and instead do it yourself, with whatever test you are comfortable with, they all are generalization tests and close color shade changes between readings, but it IS a decent baseline to get a general idea of what's going on, BASICALLY just used to determine when you should water change.
Heck, water change like I said. aim for 100% of the tanks water being changed each month whether it's 2x 50%, 4x25% 1x75% and 1x25% 10x10%.
Maybe there is ammonia in the tap water, that goes into the tank and the tank and cycle has to deal with it like it's supposed to. Even if that's the case the fish need to have an actual problem and the fish have actual stress and/or dying from it for it to be an actual problem that needs correcting.
IF that's the case where its injuring or killing fish, and the pH is high and the ammonia is high and then lower the pH below 7.0 with
driftwood, or humic substances, or
peat moss, ect. ect and the ammonia will be even less toxic at a lower pH.
Don't fix it if it ain't broke. Water change as you normally would to maintain the tank, Do your own water testing with whatever method suits you and is easiest for you to understand and use, it's all the same, general tests with color charts clearly not meant for the colorblind. LOL.
if the fish aren't sick or dying, are eating well and swimming around and growing, and look good, I don't see a problem whatever the tests or the stores tell you.
Just being honest. All the best to all yall!