You should be able to get the reading from your water company.I also have hard water here in Stoke
OK, that does explain things a little more clearly. I can just use our tap water (from a deep limestone aquifer) to buffer rain water if I need to raise the hardness.ShrimpSoil used with RO that already has a KH of zero has resulted in a dramatic pH swing, if I were keeping Gouramis this substrate would be ideal but I'm not. If I were to stop with the RO and use tap I would still be facing the same problems as my water comes out the tap with a TDS of around 30, so I'd still have to remineralise the water before using it. The pH is still dropping, not sure if I should rip it out and put gravel back in.
I don't know Stoke, so it was either that or the Britannia Stadium.I live close to Trentham Gardens