Well, I know what I did: I killed it. But I'm trying to figure out what I did that killed it and how I can remedy that problem.
I haven't checked my water params in a few weeks because I found out my test kit was too old and the chemicals had gone bad. (Found this out when my nitrAtes tested 0 in a goldfish tank; if only /sigh) I tested my 10 gal divided betta tank today and got these readings: ph: 6.6 (understandable, I have a bit of driftwood in there); Ammonia 0.25ppm; NitrIte: 0ppm; NitrAte: 0ppm.
The tank they are currently in has been set up for 4 years and previously had kuhli loaches in it. The bettas have been in it around 3 weeks (moved them shortly after I found out my test kit was bad). Right now it houses 2 male bettas (divided of course), about 5 ramshorns, 3 anubias plants, and a carpet of duckweed at the top. I removed the power filter when I added the bettas because I didn't want the flow to bother them. I also began feeding the bettas a little more (2 pellets in the morning, 1 bloodworm in the afternoon, and 2 pellets an hour before lights out) starting a few days ago. The fish are showing no signs of stress or disease.
Could it be that the increase in food caused an ammonia spike? Did I really kill my biological filter? What can I do to fix this?
Appreciate the help! Thanks in advance!
(Also figured I should note that I do about 30% water changes weekly.)