Thank you, Helene – no problem!!!
No, I will do it as I planned from the beginning – in the small tank only one pair of paros.
And I think I will not try to change the water parameters in the bigger tank. It’s a bit too risky – I don’t think that I will really be able to lower the conductivity from 250 to 50 µS without emptying the tank and removing the soil.
I think I’ll keep either Pseudosphromenus and Boraras (Asia set up) in the 120 liter tank – or (rather?) Microctenopoma ansorgii together with Aplocheilichthys normani or myersi (Africa set up).
And I will make a first try with a single Parosphromenus pair in the 27 liter tank. And then …….. let’s see….