Thank youIn the wild, what triggers breeding in many freshwater tropical fish is rainfall. Rain has an acidic pH and dilutes bodies of water. So gradually cutting your water with RO or Distilled (pH of 6) will simulate heavy rain. You can also add leaf litter and pieces of tannin-heavy driftwood like mopanI or Malaysian bog wood, which will stain the water and also lower pH.
Do not use chemical agents such as Perfect pH. These cause unsafe parameter swings and are temporary solutions.
You can try some of these safe methods:
if fish live in 100% RO water,we need to suply mineral and vitamin through foot sources so fish / plants can growRO (distilled) water water has a pH of about 7. So you'd need to go 100% R/O. Lots of research though because you'll need to augment the water with minerals (magnesium, calcium, manganese etc.) and some electrolytes like potassium. And then add peat, wood, IAL and hope that brings the pH down further.