Moving from soft to hard water

[Chris_Homan]

Hi All,

Unfortunately my apistos didn’t survive into old age and now I’m considering slowly switching from 60% RO to hard tap water. Our tap water is very hard at 360mg/l (20dGH). The remaining fish (red phantom tetras, otocinclus, cardinal tetras) had been store bought in hard water (not sure what exact hardness) so should hopefully be okay with this level of hardness. I usually do 40% water change every week. I was thinking of doing a 40% water change with 30% RO at first (adding it very slowly) and then the next one with 0% RO. Is this safe or too quick? Or not a good idea at all?

 

[Hufsa]

If you could do it a bit more gradually I would, unless you are in a hurry then there is no reason to rush it?
If you could increase the hardness by no more than 1 degree KH per week then that would be the safest way to do it.
I dont have personal experience with doing it but this figure is often quoted by fishkeepers and is said to be safe.

 

[Chris_Homan]

That sounds doable, thanks!