Hello. My DH wants to have a fish in his study. We are going to start simple with a large glass bowl. I have a few questions; 1) is tap water with the water safe stuff ok, some websites say to use bottle water only 2) We have a cat, will it try and get the fish, if so any ideas on covers 3) suggestions on an easy starter fish and lastly 4) do fish need company ie shall we get one or two?
Bowls not good; need large surface area for oxygen. Get the largest tank you can afford/fit. As a rule, you get an inch of fish minus tail per 10 litres of water, but different species are more or less demanding. Some need to be in groups, some need to be solitary.
Stick to freshwater not marine, then decide tropical (small groups, pretty) or coldwater (goldfish). Tapwater with dechlorinator may be ok, but some fish need soft water so can't cope with hard water.
A tropical setup will have heater and lights under a lid, which solves the cat problem. Actually tanks usually come with lids.
A new tank needs some weeks to build up all the bacteria etc needed for happy fish, so don't expect to take a tank and fish home the same day, and don't go back to a fish shop that would let you.
Have a look at a fish shop and ask questions. You'll need a bit of effort to start then about 30 min or less maintenance a week. All worth it!
Go and have a look around a shop to see if anything jumps out at you. Go to a specialist place, not a general pet shop or garden centre with a fish section, and make sure you do your own research as well. Some fish shop staff can't tell the head end of a fish from the tail end, but some are geeks with endless knowledge about obscure fish. Maidenhead Aquatics are generally pretty good and there are lots of good little independent shops too.
not much help to you, but if you have a fishtank and a cat, the two will almost certainly mix, my cat sits on top of our tank! even though we shoo her off. a previous cat when i was a child did used to go and sit on top aswell when we kept fish back then, 25 years ago...its a cat thing also, some fish jump, my friend, who has no toddlers! found her weatherloach on the floor, no idea if he climbed or jumped, she has nooo idea how he got there??? so a lid of some sorts is very advisable