https://www.whogivesafish.com/forum/
I was also racking my brain, trying to recall the name of those RO stations, and now I'm pretty sure it was you who mentioned them to me earlier.angelica wrote: ↑Fri Jan 10, 2025 6:18 am I used to keep soft water fish in hard water, thinking it wouldn't be an issue. But in hindsight, I can see the impact it had on their lifespan - my cardinals and other soft water fish averaged 12-18 months. Since switching to RO water, I've noticed a significant difference. The same species are now thriving, with an average lifespan of 6-7 years. The change has also had a profound effect on their appearance, with much brighter colours now on display.
Spotless Water is a company I came across - my partner actually uses their services for window cleaning. Not something I use personally, but you might have one in your area.angelica wrote: ↑Fri Jan 10, 2025 6:18 am I used to keep soft water fish in hard water, thinking it wouldn't be an issue. But in hindsight, I can see the impact it had on their lifespan - my cardinals and other soft water fish averaged 12-18 months. Since switching to RO water, I've noticed a significant difference. The same species are now thriving, with an average lifespan of 6-7 years. The change has also had a profound effect on their appearance, with much brighter colours now on display.
It's actually boomer who's familiar with those studies. I recall reading that cardinal tetras kept in hard water developed kidney deposits, which supports the idea that long-term exposure to hard water can be detrimental to these fish.belleora wrote: ↑Fri Jan 10, 2025 8:01 am I've been thinking about this a lot, and from what I've gathered from discussions here (maybe @boomer or @sSjey can dig up the studies), it seems that soft water fish have evolved to hold onto minerals when they can, since they're scarce in their natural environment. On the other hand, hardwater species like mollies have adapted the opposite way.
The issue with keeping soft water fish in hard water long-term is that the damage is cumulative. Over time, the minerals they retain can cause blockages, particularly in the kidneys, which ultimately leads to a shorter lifespan.
I'd love it if someone could share the research to back this up - I'm sure I've seen papers on this shared here before, but I don't have the time to track them down right now.