OK. This one is for you highly experienced members out there, (shout out to @Discusluv ) Yesterday I did a thorough-ish gravel vac and 40% water change on my 60 gallon community. (2 half-grown angelfish, 1 DG, 5 black neon tetra [will top off the school after my vacation]). I have noticed recently that nitrates are creeping in this tank, despite 40% weekly water changes, nitrates stay around 25ppm at my weekly water tests (API Master Kit). That seems high to me considering the light stocking. I suspect I may be overfeeding and/or leaving too much food in the gravel. Gravel vacs reveal a decent amount of spilled micropellets, which I carefully hand sprinkle on hardscape for the growing angels, who are a little messy. My tap water has at least 5ppm nitrates in it already. Tank has been up since February, not exactly mature, but the tank cycled months ago, evidenced by many weekly water tests showing zero ammonia, zero nitrites, and rising nitrates. Yesterday I tested 5 hours after a gravel vacuum and a 40% water change. I don't usually test after a water change. Strangely, there was 0.25 ppm ammonia, and 0.25 ppm nitrites. Nitrates were still at 25ish. So, after this water change, I decided to add 2 more buckets (8 gallons) to my weekly water change regimen to bring down nitrates, maybe re-think my feeding strategy, and to post a thread if the ammonia or nitrites persisted for a couple days. This morning I re-tested. Ammonia has gone down to just a trace of green, way less than 0.25ppm. Nitrites still near 0.25ppm, maybe a tad under. Nitrates 25. I was going to wait one more day to post, but I've learned today that 0.25 ppm nitrite is worse than I previously thought. Questions: 1. Should I really salt this tank? Or can I wait another day or two for the BB to catch up? 2. Is this a clear indication that I am adding too much food into the tank? I truly am not feeding a huge amount in my mind, but these pellets do tend to break up and scatter. When I cut back a little on feeding, the angels get dramatically more aggressive with each other at feeding time. I take that as a sign that they are hungry. Perhaps I could vacuum more often, doing 2 water changes per week? More alarmingly, I tested the betta tank today, which is also pretty new, but has been completely cycled for weeks. It also had 0.25ppm nitrites in it this morning! In no way is there any possible overfeeding going on in this tank. A single male betta in a cycled 10 gallon. 40% weekly water changes. Changed yesterday. Ammonia has always been zero, nitrites zero, nitrates 5ppm, until today. I immediately suspected the tap water, as this is quite the coincidence. Tap water reads zero nitrites. What is going on here? I want my fishies to have the best environment I can provide, their health is paramount to me. What can I learn from this? I've seen cycle bumps before on past tanks, usually minor and lasting one day, but this seems like a strange coincidence. Nothing out of the ordinary has happened in either tank that I can think of, except that they both were vacuumed yesterday during the weekly 40% water change. Sorry for the novel. I just like to be thorough! So should I salt? Am I adding too much bioload? Thoughts? Teach me, please. Thanks!