Do I need to worry about acidity and alkalinity ?
PH is the measure of Acidity and Alkalinity using the PH scale which goes from 0 to 14. 0 Is extremely acidic, 14 is extremely alcaline, with 7 being neutral.
Fish commonly found in aquaria came from vary diverse backrounds before they ended up selected for the aquaria hobby. Many of these specioes are now commercially bred for the hobby, and it's been many generations since the species lived in the original habitat with it's specific water type and PH
Some species, including many Tetras, originally came from acidic tropical rainforest rivers and streams where the water was very acidic, and full of peaty leaf litter. Other fish come from evapourating ponds, or water sources which crosses rock with a high mineral content which causes the water to be very alkaline.
The beginner to the hobby should be reassured that most tropical fish suitable for the beginner will happily survive any water PH within the range of UK tap supplies.
Our advice is to test your tap water, then test the water in your aquarium once established. If it's between the PH range of between 6 and 8 you should be OK. The fish species listed as suitable for beginners
The fish species listed as suitable for beginners on this site indicates their preferred PH range.
If your water is radically far away from neutral, it might be wise to select fish bearing their preferred PH range in mind.