I've decided to start keeping tropical fish but there's so many different varieties I'm not sure where to start.
I was thinking of getting a 60 litre tank. What fish could I keep in a tank that size? I'd like a group of tetra to start with and then a couple of other species of fish if possible, preferably ones that are fairly easy to keep and won't try and eat each other!
So how many tetra would be a good number? Is 8 ok?
What else could I keep with them? I like the idea of having a catfish, and maybe some barbs?
Most tetras don't do well in hard water. There's a couple of exceptions, but the "liquid rock" common in the UK is still a bit much for them. Livebearers, some barb species, and the smaller rainbowfishes would be a better choice.
great_khan I do like the look of the Juwel ones, I'll have to save up a little bit though.
Is there any way to soften water? Or find out how hard or soft the local water is? I will of course test the pH before I get any fish once I have a tank that's been up and running a while. Also is it possible to alter the pH or is it pretty much what you get is what you have to work with with water?
As I said I'm totally clueless about fish keeping but I want to learn!
You can find your local water hardness on your supplier's web site on the page for water quality. There should be a box to type in your post code which will give links to a full report.
The only reliable and useable method for reducing hardness is to mix RO water (water which has had all the hardness removed) with your tap water to dilute it to the needed level, or use 100% RO and add back sufficient minerals for the fish you want to keep. pH can only be altered in any useful way by the same method as pH depends on carbonate levels and these can only be reduced by dilution or removal.
Fish need to be selected to suit your local hardness and pH unless you are prepared to go down the RO route. pH needs to be tested once straight from the tap and then again on a sample left to stand for 24 hours in case it changes drastically (it often does as temporary adjusters used by the suppliers gas off in that period). The pH after 24 hours standing is what you will use to choose fish as that is where the tank will tend to stabilise after cycling when regular partial changes are being done.
It's possible the pH will rise when the water is left to stand. A lot of the utility companies alter the pH temporarily either to improve flavour or to protect pipes from damage. It sounds as though you'll need to look at fish who like hard alkaline water - livebearers like Mollies, Guppies, Swordtails and so on. Was there any more detail on how hard? Or a link to a pdf with a full report?