Book Clarification

Discussion in 'Discus Fish' started by bluOlive, Jul 10, 2015.

  1. bluOliveNew MemberMember

    Here is the content I'm reading.

    "How water quality affects osmoregulation

    A fish's osmoregulatory system is designed to match the conditions found in it's natural environment. Soft water fish, such as discus and tetras, are accustomed to water with a relatively low salt content, so their osmoregulatory system is designed to retain as many salts as possible, vital for normal bodily functions. If the fish is placed in hard water, which typically contains high levels of calcium, it may be not be able to remove enough of the excess calcium, since its osmoregulatory system is optimized to retain salts, rather then remove them. The excess calcium in the body is then deposited in the kidneys, causing damage and further reducing the kidneys' ability to remove substances."....

    OK so question is. I have very hard water. Do I add salt? How much for a 55 gallon. How often would I do something like that??
  2. hampalongWell Known MemberMember

    No you do not add salt. The 'salt' referred to here is not sodium chloride but the metal salts that go to make up hardness. Totally different. :)
  3. Anders247Fishlore LegendMember

    Nope, don't add salt..... hampalong, thanks for that info, I was confused with things like this in my books as well.
  4. hampalongWell Known MemberMember

    It's not often explained well in fish books. Metals form 'salts', they're just a certain type of molecule, with a metal ion and an ion of something else (I'm not a chemist), sodium chloride is one, and it's so familiar we just call it 'salt'.

    Freshwater fish do not benefit from 'salt' (with a few exceptions that live where freshwater meets brackish). its use is as a disease treatment, but it's tolerance levels vary among fish types (fish that evolved from marine fish, such as the cichlids and Livebearers, are more tolerant than say tetras and catfish, etc...)

    Hardness, on the other hand, is about the quantities of all the other salts, which are mainly just a few, in water. Hard water has more than soft water.

    Wild caught discus wouldn't last 2 minutes in your water (bluOlive) but fish are adaptable, and some discus have been in captivity for many generations and these are more adapted to harder water. Same with Rams, and other common soft water species. It's actually easier for a soft water fish to adapt to hard water than the other way round.

    You can 'cut' your water with RO, Reverse Osmosis water, which is pure (as near as). This will dilute the hardness and give you softer water.
  5. Anders247Fishlore LegendMember

    Yeah, I remember reading that. That's why I prefer harder water and high pH, among other reasons.