... It is on the far side of the tank from the filter and over a huge wad of hornwort. I think the problem is the floating plants. They are spreading so fast, it looks like they have already broken it up some more by growing all over it.
Quick growing plants are not a problem. That gourami,
Trichogaster chuna, can thrive in neutral water, so plants are part and parcel of its breeding. Makes perfect sense that it's on the far side of the tank from the filter and over a huge wad of hornwort
lol, he will be doing this all spring long... more than enough time to practice... just leave him, he has more than enough building materials there. by starting his nest he is already approving of conditions.... don't change stuff now.
I agree whole heartedly that by starting his nest he is already approving of conditions. That's one reason why I always want to breed whatever species I happen to have, it's the clearest indication that ideal conditions have been provided. Your gourami are doing this all Spring long, what about Summer, Autumn, Winter? Seasonal spawners in the wild normally become perennial spawners in captivity, unless we drop their temperature, decrease the food supply, etc. I once had a
Macropodus hongkongensis that maintained a nest for >3yrs and may have maintained it longer if we hadn't had to relocate. It's a territorial marker and breeding site in one.
I don't what it is with this tank as it doesn't seem like anything special but it must be like the fish disneyland. ...
The best tanks for propagation IME are not special, they're just simple, basic set-ups.
All those floating plant roots are teeming with microbes and food for baby fish, parents know it, and are maximising the amount of offspring that will raise maturity.
For that species and for all neutral/alkaline species maybe yes. But there are nearly 100 blackwater species that breed in sterile water completely devoid of plants and microbes. In fact, when they're brought into our high pH planted tanks not only do they not breed but they succumb to infections within days.