pick about pH? - Tropical Fish Keeping - Aquarium fish care and resources
 
LinkBack Thread Tools
post #1 of 3 Old 08-18-2011, 03:33 PM Thread Starter
Member
 
pick about pH?

I've been browsing several of the fish profiles and notice that very few profiles recommend pH's higher than 7.5. i have a pH of 7.8. is this likely to be an issue for many fish? obviously, anything that needs acidic water won't like it, but very few seem to actually like alkaline water.
KendraMc is offline  
Sponsored Links
Advertisement
 
post #2 of 3 Old 08-18-2011, 05:23 PM
Member
 
a few that prefer harder water: liverbearers including guppies, platies, mollies, swordtails; African cichlids including kribensis; some rainbow fish and killifish
sik80 is offline  
post #3 of 3 Old 08-18-2011, 06:00 PM
Member
 
Byron's Avatar
 
As the one who has written almost all of the freshwater fish profiles, I may be able to help a bit.

I use the pH and hardness "numbers" that are the consensus of acknowledged reliable sources, many of them biologists. It is quite amazing how very few times I actually find a varying number, which of course gives weight to the reliability of the sources.

Some fish have considerable adaptability when it comes to hardness and pH--and one must remember the hardness is just as important to the fish's health and hardness and pH usually co-relate. Some fish do not. Many of the "adaptable" species will manage but show some form of obvious dislike, and that is mentioned where I have scientific evidence of the fact.

A difference of .2 or .3 is not likely to make much difference. But a number has to be given or else we have a wide-open field. Saying this particular fish requires a "slightly basic" water can be interpreted differently by different people, so a number is given as the "high" end. If I use 7.5, I would expect 7.6 or 7.7 to be non-problematic; but if I used 7.7 then others may assume 7.8 or 7.9 is OK. So there has to be a number ceiling to avoid confusion.

Last comment is that most of the fish in aquaria are soft water fish. There are simply more species in very soft acidic waters than there are in basic harder waters, simply because the waters in the tropical rainforests are by nature very soft and acidic, and that is where species evolve at astounding rates.

To illustrate, only this past week I came across a recent scientific study on the Black-winged hatchetfish (published in February of this year). Up to now, we have known this fish as Carnegiella marthae, which has a natural range throughout the floodplain of the Rio Negro basin, and there is a near-identical species in the Peruvian Amazon known as Carnegiella shereri. I happen to have both. The recent study examined fish collected throughout the Negro floodplain, with the unexpected result that there are now three distinct species of black-winged hatchetfish. Eventually they will get described and named. From the description is is possible I have two of them; I have long wondered at the difference in patterning [if interested, you can read more in our profile, I just revised it this week]. These three distinct species have evolved in isolation [though two of them were caught together in the same net] within the same river system. The dwarf pencilfish, Nannostomus marginatus is a similar example; the new species N. mortenthaleri and N. rubrocaudatus were initially thought to be simply colour variations, but are now recognized as distinct species that have evolved independently from a common ancestor simply by being in different creeks.

Byron.

Byron Hosking, BMus, MA
Vancouver, BC, Canada

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian. [unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]
Byron is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome