Hi. It's hard to say; it sounds like you're in the nitrite phase, which can last about 3 weeks on average from when they started to spike, so you might have some work ahead of you (and some patience lol). WIth nitrite at 3 you'll want to get that down ASAP. If you do a 50% water change (with dechlorinator and match the temp of the water as close as you can), it should bring the nitrite down to 1.5, which is better, but still fairly toxic, so another 50% water change would reduce that by half again. If I were you, I'd do 2-3, 50-70% water changes back-to-back to get that down. Do two, then wait an hour, test nitrite, if it's over .5, do another. Once you get them down they'll likely spike again, so you want to stay on top of testing and water changes to try to keep the nitrite as low as possible until the tank cycles.
