[Peter Finke]

Marcin, some remarks:
1. I should never try to breed licorice gouramis in a fully empty tank even without any surface plants. I use at least some javamoss and Ceratopteris at any case and leaves or peat on the bottom, and even some small roots, too. Mostly, that makes things easier.
2. You need not to see “everything”. You need to see everything happening in the cave. Place the cave in such a way that you have a good view in it using a torch.
3. It is very risky indeed to keep several species of Parosphromenus together in a community tank. If you don’t mean males only but females, too, I wonder if you would be able to select the “right” females if you want to breed a species. This keeping-together is possible in quite a small number of species only, but very hard if not impossible with the great majority, especially nearly all species (and other forms!) of the bintan-related forms with a rounded tail. We are not sure whether the males could achieve this at any rate; mind that we have no information on the closeness or distinctness of species (or subspecies?) so far. Such a community tank is only an alternative if you have a very well-chosen selection of forms that allow to recognize the females without doubt (or you have so many fish self-bred that you don’t need them fro breeding again). Otherwise the risk of producing hybrids is high. I hope that your hitherto failures are not due to that factor.
4. The caring males try to remove snails from the inside of their caves. They do not feed on them, but try to bite them away. But they don’t succeed in any case. The only thing one can say is: In breeding tanks there is no room for snails as long as there are eggs and larvae within the cave. At least one should try.
5. The caring male should be left as long as possible. It is possible but very difficult to raise eggs without the help of the male. It is impossible without use of effective chemical means against funghi. The males work very effectively in this respect. They will find and remove any bad single egg.
6. The male should (or could) be removed when the young leave the cave. This is not the same moment for all, it can differ from hours to one day. The young will swirl around within the cave a long time (days) before they leave. The father will put them back to the nest, at least he will try (but rather effectively).
7. The thing becomes difficult if the pair has spawned a second time shortly after the first; that happens. Then you have larvae and fresh eggs mingled together at the ceiling of the cave. Then it is best to leave the male at the place and give shelter to the young by the leaves on the bottom and the swimming plants at the surface. Many males (and females) don’t harm their young, but some do.
8. Extensive breeding is the best way to first successes (= leaving the pair in a highly structured breeding tank and feeding it with fresh small Artemia naupliae that could taken by the young, too). Intensibe breeding (= breeding without the permanent presence of the parents, breeding for quantity) is much more difficult. One should learn it, but later only.