General question

[Neithan]

While browsing through the various threads and sections here I've noticed something that makes me wonder. Why do people keep fish that need hard, alkaline water (like platys, swordtails and most guppies) with fish that need soft, acidic water (angel fish, tetras, most if not all corys etc)?

If you have lots of problems with fish getting sick or dying for no obvious reason, take a good look at your tank - the water itself being unsuitable for that particular fish might be the cause of this. The average lifespan of most tetras for example is well over 6 years in the proper environment, a goldfish can live for 30-40 years. The only fish I've so far heard of having an average lifespan of less than a year is the male betta.

I've always been of the opinion of 'each to his own', but it does make sense to choose the fish so they will thrive in your tank for as many years as possible, instead of buying new fish every year or so just because the previous inhabitants died for whatever obscure reason.

I'm not posting this to be mean, I'm merely used to a forum where people practically lynch you if you keep platys with tetras or angel fish in a tank that isn't atleast 50 cm high, not to mention keeping goldfish in a smaller school than 5 fish and a 500 liter tank =P

[Abbeys_Mom]

Endler's livebearer male only live have a lifespan of a year or less. They average the lifespans for both sexes, and the females live for 3 or more.

[Lady Hobbs]

You've brought up an excellent question. Fish are best suited in water with their own requirement. Often you will see here that people with hard water with high pH are recommended to stick with cichlids. It's easy to raise the pH but not to lower it so purchasing fish that do well in your own water type is best.

I have hard water with a pH of 7.6 so obviously will not be getting Discus. I just don't want to fight with the pH all the time.

The recommended pH for fish is taken from the area the fish come from originally, as well. Not many fish are imported these days and many of the countries they come from is no longer allowed the export of them. They are mostly farm raised now and are kept in huge tanks made of cement in the hatcheries. They are used to different pH now and can take the functions more readily than a fish that's been imported right from it's natural environment. The fish we buy come from hatcheries all over from CA, TX, FL, etc. and all are raised in what pH is available to them in different area's and from different fish breeders. Fortunately, the pH has some leeway with most kinds of fish. For instance, pH for cichlids is 7.6-up to 8.5 and some even higher so we get some play room there.

The temperatures not being right for fish is a bigger problem, I think. You see (all the time) those that put goldfish with freshwater fish that have a totally different temperature requirement......along with the fact they don't belong together ever. You also see people keep angels in a community tank. Angels should have a temp of 80.....not 74 or 76 and it's thought to be one of the contributors of HITH. Cold fish=stressed fish=diseased fish. Same thing for fish kept in water too warm for them.

I consider the temp of the tank actually more important than the pH. Fish will adapt to a steady pH more readily than they will a steady temp not suited to their needs.

[Neithan]

All very good points hobbs, thank you for pointing them out. However I do believe it's a combination instead of one single element that makes fish thrive. If you have all the other aspects in order, changing one slightly wont dramatically affect the fish. Hence why they do have the spectrums of what conditions they tolerate :) Some are obviously more tolerant than others, like for instance the common (here) bristlenose catfish.

We don't have many hatcheries in Finland (most are just private persons breeding a few species at home), and since the water conditions vary greatly according to where you live, it's sometimes baffling how different water can be. Fish from one petshop will thrive in your tank while fish from another one die within a week, due to differences in where they get them from.

It's always a good idea to check your tap water before starting to plan on what fish to get, however even that isn't always reliable. In my case for instance, the water has a pH of 8 when it leaves the waterplant, by the time it reaches my tap it's down to 7.5 and in the tanks it's closer to 6. In the large tank it's as low as 5.5! The only reason I can keep applesnails is that I made an investment in a stone I can't for the life of me remember the name of. Limestone perhaps?

I also agree on the temperature being more important than people give it credit for. Goldfish kept with tropical fish is one good example of a fish that likes it cold, another is bettas and gouramis, which both thrive in still, heavily planted warm water.

Abbeys_Mom, thanks for the info on endler's, as I don't have much experience with those. I'm aware there are more than betta males that don't live long, but since that was the only one I could name... :)