Is it my imagination or do tank raise fishes have a harder time adjusting to acidic water then wc fishes to more neutral water.

[anewbie]

So i'm making some assumption that the issue that tank raise fishes have with very acidic water (below 5.5) is the difference in bacteria but my observation seem to be that buying tank raise fishes frequently lead to infant death (first 2 weeks) but wc fishes do fine but conversely putting wc fishes in tap water (here tap water is tds 130 ph ~6.9 to 7.1) seem to have little issue.

So I guess i'm asking if this is my imagination or a known issue with tank raise fishes and low ph aquariums and why one direction is easier to adapt then the other direction.

 

[Mike Wise]

I think it is your imagination. With 50 years keeping apistos, I've found that fish, no matter if wild or domestic, adapt to water values as long as the fish have been shipped properly (no ammonia damage to gills) and acclimated gradually to values not overly extreme.

 

[anewbie]

I think it is your imagination. With 50 years keeping apistos, I've found that fish, no matter if wild or domestic, adapt to water values as long as the fish have been shipped properly (no ammonia damage to gills) and acclimated gradually to values not overly extreme.

I should mention that I'm seeing the issue more with tetra then with cichild but i did have a group of domestic ram immediately develop bacteria infection when put in discus tank - of course wc rams did not have this problem. While the source was the same it could have been a bad batch of fish from wetspot or something latent in the aquarium which does not impact the other inhabitants. I did cure the issue by hand feeding the rams (they are very friendly) some kaplnax laced food.

 

[MacZ]

It is always easier to adapt a fish used to soft and acidic water to harder water than the other way round. So... it's correlation but not causation.

 

[anewbie]

It is always easier to adapt a fish used to soft and acidic water to harder water than the other way round. So... it's correlation but not causation.

Can you explain why and is the issue the different type of bacteria in the water or the stress in change of mineral content or is it more empirical and less scientific ?

 

[MacZ]

The ion exchange in via gills and kidneys is the key factor here. You have two different scenarios usually.

A. A softwater fish, with anatomical adaptations in gills and kidneys, being moved to less soft water actually gets some relief at first since the tissue responsible doesn't have to work against that much osmotic pressure. It has been anecdotically reported that these fish kept in really hard water tend towards kidney stones and gill problems.
Conversely a fish with adaptations to harder or even saltwater is used to lead ions out of the body. Result in soft (or freshwater): The fish loses ions like Sodium or Potassium faster than it can refill those from food.
In both fish the gill tissue can adapt to a degree (and quite quickly, according to studies the gill adaptions can be done as quickly as 24h) making it possible with some health problems.

This explains why the move from soft to hard is easier than the other way round.

B. If you have two fish of the same species, one having to adapt from hard to soft and one from soft to hard, the same principle applies.