It seems like every question leads to more questions, blackwater fish are apparently just as difficult as they are rumored to be.
Here are some questions presented as coherently as I can manage-
1. I am using Sera peat granules for filtering, maybe instead of or in addition to testing the water to find out when they are no longer altering the water the way I want them to, I could just frequently replace them with new peat before the old peat loses its water softening properties. Even in r.o water, once the peat whas broken down there’s a danger of hardness and ph rises?
2. There is a sponge filter from a dismantled aquarium being used in my tank, it was left out of the tank for days and remained wet and I am hoping it will help cycle the tank with either live nitrifying bacteria or the waste it will add to the tank if it is just a dirty sponge that will introduce pollution. Is cycling a blackwater tank any different than cycling a normal tank? Ammonia to nitrite to nitrate, just test the water and when it turns into nitrate the tank is cycled?
3. I have decided against chocolate gouramis, the tank is not really big enough for such mean fish. I want to have a large group of licorice gouramis. Perhaps this will show their natural social behavior, their own sheltered area with lots of conspecifics. It’s about 20-25 gallons of water so would 7 fish (and hopefully babies eventually) be an ok stocking density?
4. What are the germ kits you mentioned, is there a brand that is better than any other? And should I use uv filtration? Seems like it couldn’t hurt.
Right now the challenge is figuring out when the tank is cycled and clean enough to introduce licorice gouramis. So hopefully this will keep progressing, and I will eventually be able to post a picture of a succesful tank with healthy licorice gouramis.