How long since you started the cycle? Cause I get readings like those on my tank that's fully cycled.
What are your tap water parameters?
It’s going to be a acrylic divider - will prevent illness spread and means my current filters and heaters will still work as each section will be same size as my current tanksIt shouldn't restart overnight. It would take a few days I think for everything to die off. As long as the filter was damp it should be fine.
Also about the split tank, as long as mesh or some sort of water permeable material is the divider, you'll be fine. Shouldn't need two filters though unless it's an acrylic or glass divider or something. Or you just want to have a back up filter for another tank lol
Even though I never had nitrites? I don’t know how it works so sorry if that question is silly or irrelevantOkay, then I'd say you're probably cycled since the tank has taken on nitrates.
I plan to use their current filters. So like a 10 gallon split using acrylic divider and in each side put each boy and his current heater and filterThen what you're going to want to do is run the other filter in the cycled tank so media can be seeded onto it. Really any filter you plan on running for you betta boys should be running in the cycled tank to get some good bacteria on it.