Tank stopped mid cycle?

[Clockwork-crow]

I've been dealing with a cycle crash since december, and last week it looks like I was getting some real bacterial growth, ammonia levels were <0.25ppm for a solid week, did a water change, then did a water change two days later because although ammonia was consistently <0.25ppm there have been elevated nitrates in my tap water, it's been 3 days after that and ever since the ammonia levels in my tank keep increasing, like it was never cycled. Test kit is two weeks old, kept in a drawer under my desk, I did shake the test vigorously for each test. What's going on? What should I do?
Also stock is:
6 CPD's+ 1 fry
8 Corydoras habrosus

in a 15 gallon tank

Also filtration is two sponge filters, one running on an APS 100 and another running on an APS 150

 

Edited February 20, 2021 by Clockwork-crow

[MJV Aquatics]

Perhaps something has caused the nitrosomonas bacteria population to subside. Stay on top of your  water changes and/or use an ammonia neutralizer as ammonia at higher levels is toxic to the bacteria as well as stock.

[Clockwork-crow]

Just tested my tapwater, seems to be at 1ppm from the tap, also yes I'm regularly dosing with seachem prime

 

[Trish]

This might not be a cycle stall at all, In my experience it's not unusual for the ammonia test to read .25 from the API master test kit.  It's probably a false positive and has been mentioned often on the internet.  My tanks have been established for years and always read .25.  You needn't worry unless your ammonia results are .50 or higher, then do water changes.   What are your nitrates testing at? As long as they come in at 5 to 20ppm you are doing great.   If your fish are happy and you see no unusual symptoms... you are probably doing just fine! 

Edited February 20, 2021 by Trish

[Clockwork-crow]

So, over the last couple of days my ammonia from the tap has been about 0.5ppm, nitrates are at about 5ppm greater than tapwater but haven't increased over the last few days. Do I just dose with seachem prime and bitch at my water company?