Quarantine Tank - Corys

[bettacarl]

Most fish stores and a lot of websites have no idea that hardness is important for fish so they only think about behaviour, unfortunately.

Yea I wish the people in the petstores were more informed, since I wouldn't have gotten the mollies if I had known this but I plan on doing a lot more research before I get more fish now. (At least I know a little bit more about my water hardness).

 

[AdoraBelle Dearheart]

I have just noticed you have mollies. Are you aware that mollies are hard water fish while cories are soft water fish? They are not compatible on hardness grounds. Depending on your tap water hardness, one or other will not be happy.
Do you have hard or soft water? You water provider's website should tell you how hard your water is; you need a number and the unit of measurement.

I know that it isn't applicable in this case since the OP has soft water, but did you know that there are a few cory species that like harder water? I had no idea! I've been moaning about not being able to keep the species I really want since I'm in a hard water area (253ppm), and @NCaquatics (thank you, lovely lady!) did some research since she knows I love cories but didn't think I could have any, and she found seven different cory species that would be fine in my water according to SF! Including corydoras sterbai and corydoras schwartzi, which are both beautiful and the ones I'm thinking about getting the most. I'm so over the moon!

I wonder if we could start a file or something that lists potential fish like bottom dwellers and schooling fish that could work in hard water? It's such a limiting option, but if people want cories and they have hard water, it would be handy to be able to link them to some potential cory species that could work.

 

[Byron]

Thank you for all the information you've given. I wish the fish stores were more informed so I could have figured this out before purchasing the mollies. I will probably rehome them if I can. Do you happen to know (I am almost 100% sure the 15 days have come and gone for the petsmart return) if petsmart would take these fish back even if I don't get money back for them?

No idea, sorry.

 

[Byron]

I know that it isn't applicable in this case since the OP has soft water, but did you know that there are a few cory species that like harder water? I had no idea! I've been moaning about not being able to keep the species I really want since I'm in a hard water area (253ppm), and @NCaquatics (thank you, lovely lady!) did some research since she knows I love cories but didn't think I could have any, and she found seven different cory species that would be fine in my water according to SF! Including corydoras sterbai and corydoras schwartzi, which are both beautiful and the ones I'm thinking about getting the most. I'm so over the moon!

I wonder if we could start a file or something that lists potential fish like bottom dwellers and schooling fish that could work in hard water? It's such a limiting option, but if people want cories and they have hard water, it would be handy to be able to link them to some potential cory species that could work.

Just to ensure there is no misunderstanding among especially more inexperienced members, it is not so much a case of a Corydoras species that "likes" harder water, but some species seem (so far as ichthyologists can tell) to manage or tolerate slightly harder water. No species of Corydoras in South America occurs in water that is not very soft, so far as I am aware. The pH is acidic, sometimes extremely so, but closer to neutral in some northern areas. I'm going from memory here, but I think this is basically the situation.

In a discussion on GH on CorydorasWorld, Ian Fuller mentioned that he uses pure RO water with zero GH/KH, and allows the pH to lower naturally without interference. This replicates their habitat waters for most species. And it solves some other issues too--bacterial problems are non-existent in such water because the bacteria cannot survive a pH this low.

 

[AdoraBelle Dearheart]

Just to ensure there is no misunderstanding among especially more inexperienced members, it is not so much a case of a Corydoras species that "likes" harder water, but some species seem (so far as ichthyologists can tell) to manage or tolerate slightly harder water. No species of Corydoras in South America occurs in water that is not very soft, so far as I am aware. The pH is acidic, sometimes extremely so, but closer to neutral in some northern areas. I'm going from memory here, but I think this is basically the situation.

In a discussion on GH on CorydorasWorld, Ian Fuller mentioned that he uses pure RO water with zero GH/KH, and allows the pH to lower naturally without interference. This replicates their habitat waters for most species. And it solves some other issues too--bacterial problems are non-existent in such water because the bacteria cannot survive a pH this low.

Thank you for the clarification, it's appreciated Yes I'm sorry, "likes" was the wrong word to use.

Do you think I should avoid even those corydora species then, if they're going to be tolerating rather than thriving?

 

[Byron]

Thank you for the clarification, it's appreciated Yes I'm sorry, "likes" was the wrong word to use.

Do you think I should avoid even those corydora species then, if they're going to be tolerating rather than thriving?

These species are likely those that are being commercially raised, as opposed to wild caught. The issue of how far a species can adapt to differing parameters is complex to say the least, and there are limits. And the geographic background of the species helps clue us in to this. I have not maintained soft water fish species in hard or moderately hard water to see how it might affect lifespan. And for many of us, all sorts of things can impact fish health; we can only try to provide the best we can. Ian said his longest-lived cory was 40 years old when it died. Few make it that far, even for him.