Goldfish cruising surface to breathe air. Help!

[MrsNoggin]

Can anyone explain a possible reason to me? Maxwell is very important to us and I'm getting quite paranoid I just will find him floating one morning. I would like to point out I'm not a complete numpty () and we have a nice big aquarium with a filter and change the water weekly, clean it thoroughly once a month, so I don't think it's the usual reasons.

He is fairly old and fat (if goldfish get fat...), but his wife Felicity is fine. We inherited them from my SIL and they have lived through student owners who forgot to feed and clean them, freezing temperatures for two years at SIL's house after that and we took them out of their tiny bowl and gave them a nice swish tank. So they are pretty tough old beans and have been fine with us for months.

But the last week or so I noticed that Maxwell cruises the surface of the water and swallows air and bubbles it out again. He is quite happy to do this for a minute or so at a time, swims down and has a pootle about and then does it again. Does this routine for five minutes or so a good few times a day.

I would really like someone to tell me this is normal. Please? Or any other ideas? I've tried Dr Google but he just tells me to clean them out...

Sorry to waffle!

It could be a water quality issue but you'd need to get a water test kit to double-check. This explains what you need to test for.

How big is the tank exactly? How often do you change the water and clean the filter and how do you do it?

Not sure exactly how big the tank is, it was label-less and on sale in our tiny little pet shop. I could measure and work it out (well, actually I probably couldn't!) but at an informed estimate I'd say I put 45 litres of water in. Not humongous I know, but a good 3x more than they have had for 7 odd years!

I rinse the filter sponge out in dirty fish water then swish it in clean weekly as I change water and replace sponge monthly as I take them out and wipe everything over and rinse out the gravel.

P.S. Do I clean them too much? DH tells me I do. But they had such a pitiful life until us, I just want them to be happy!

I can't actually check out the link ATM because I'm on my moody phone and it's refusing. Will have a look this evening. Thanks for your superswift response!

Well when you check the links later you will need a cup of tea or a very large gin because all this might come as a shock.

Goldfish get massive and need lots of room otherwise they become stunted (which causes all kinds of health problems). This explains about tank sizes and life expectancy in goldfish.

Your cleaning regime isn't quite right, you need to be changing around 20-30% of the water weekly (make sure you use dechlorinater!) but you are spot on about rinsing the sponge in water from the tank, never ever tap water. You shouldn't be throwing out the sponge every month though, only when it's lost its elasticity- unless it has carbon in it, does it have a black section?

You shouldn't ever remove the fish and clean the whole tank though, they need some bacteria in there to process their waste. This explains all about bacteria and fish poo

Ah, so I am cleaning them too much! Will have to change those habits discreetly, lord forbid DH should notice and have a crow!

Thanks very much for links, will have a good look later, with a nice cup of tea - gin makes me cry, and I won't need that!

I always knew they need more space really. I remember reading 9-10 gallons each when we first got them, but I thought maybe they had been so squashed for so long that a huge change might be a shock. That and ours was the biggest tank I could get my hands on at the time . But I have to say Maxwell has grown a good cm since we acquired them, and Felicity (one of those poncey pretty ones) has put on an inch or so! She kind of dwarfs him now. (I actually have no idea as to sex...) I guess my theory of them being stunted for life is pretty much out the window if I'm honest .

Oh yes, definitely keep it quiet that he was right!

9-10 gallons each is about right but the minimum for a couple of goldfish is about 30 gallons (135-ish litres)- freecycle is great for getting fish tanks and ebay has loads on there at the moment dead cheap because everyone is selling and hardly anyone is buying so you should be able to land yourself a bargain. It won't be a shock for them, they'll love it! They might not grow to their full potential size if they're already stunted but I'm sure they'll have a few more inches in them once they've got the space to stretch their fins a bit.