how do you increase water TDS?.

[Mr Pleco]

Our tap TDS is 50-90

Crushed coral will boost TDS yeah

I needed an RO unit to get my liquid river rock tap water under 80 TDS , then added a DI unit to get to zero... I stopped messing with the water, measuring TDS and PH years ago.. just run tap through sediment and carbon blocks now.. stimulate breeding with temp and light only. GL keep us posted on results.