Hi!
There is a lot to tell you, clearly. First of all, really cool you started keeping paros!
They are great fish to keep, but there are quite some downsides too.
I see you are keeping them with Tanichthys. Sorry to say, but those are probably the worst tankmates one could choose. They come from completely different habitat types and their requirements are alike. Parosphromenus come from highly acidic peat swamps, wile Tanichthys come from swiftly-flowing mountain streams and even survive winter here in the Netherlands. For the latter, this is not a big deal. They survive everything. Paros, on the other hand, definitely do not. They probably survive in your tank since you have two of the easier species(but they don’t get nearly as beautiful as when kept well!), but they will not proliferate. One should keep in mind all species of Parosphromenus are severely threatened by human activity. Therefore, emphasis should be on breeding them, not just keeping.
Astonishingly, they are able to get enough food in your tank with two of the most voracious species I know, namely Tanichthys and neon tetras. In most alike cases the paros die from starvation when kept with similar fish.
Especially P. filamentosus is not very hard to breed(for a Parosphromenus, that is) so I strongly recommend setting up a small breeding tank. 20 liters is sufficient. Use RO or rainwater and put in a lot of oak leaves and/or peat to get the pH down to 5 or so. Feed them a lot of live food and with some luck you’ll be able to get some youngs.
How many of both species do you have?