Hello & Advice About My Hard Water

I'm a few weeks in after my decision to go with RO Water.

I'm glad I bought myself a TDS meter.

The first weekend, the day before putting in the first fish, I drained the tank and filled with 50L of RO and then used Tap Water for the rest.

I tested with the TDS meter and ended up with water of 180ppm hardness which is within the range of tolerance (recommended 18 – 215 ppm) for Cardinal Tetras.

Now, whenever I do a water change (currently about 10% twice a week) I fill with RO and then test with the TDS meter and add a small quantity of tap water to keep the hardness up around 175-180ppm.

I thought it might have ended up being a hassle but it's no more awkward to manage than using water straight from the tap, albeit apart from the fact that I'm going to the LFS each week to fill up with 25L RO.
At £3 per 25L it's not breaking the bank either.

I'm glad I made this choice, I'm happier knowing that the Cardinals are in more natural water.