Converting an established tank to RO water

[OwenJ]

I’ve had my 30L tank running for 8 months now and I’ve been struggling with hard water (GH-16, KH-12) so I want to start adding 50:50 RO water and tap water to soften it. I currently have 8 CPD’s, 2 amanos, 1 cherry shrimp and a nerite snail and I don’t want to upset them by doing this. What would be the method of converting an established tank to 50% RO water? I usually change about 4L of water weekly.

 

[bazz]

If you're only changing 4l in a 30l tank I can't see any problem going with 50/50 straight away, You're only replacing 2l of tap for RO, it will take quite a while to reach equilibrium but that's OK.