goldfish experts - any suggestions about why our goldfish died?

[Nighbynight]

2 small goldfish - 45 litre tank with blower thing - they have lived in it for about 2 1/2 years.
Yesterday I cleaned the tank, replaced about half the water with treated tap water.
Cleaned the filter, and put a new tablet with friendly bacteria.

Goldfish were in a bucket in some old tank water while I was cleaning the tank.

In the evening, fed them as usual - this morning, both goldfish were dead.
what have I done wrong???

Did you allow the tap water to come up to room temperature? (I'm not an expert btw)

no, it had max an hour in the room, before I put the fish back in. It was mixed with the remaining water from the tank though. Would that have caused a big enough temperature difference to hurt them?

You seen to have done everything exactly right. How sad. Had the bucket been used to hold anything else other than the fish before eg bleach or anything?

I thought I had done everything right. I dont want to get more goldfish now, as am afraid of killing them.

I rinsed the bucket well, it was our rubbish bucket actually, as our other one had suddenly sprung a leak. But mostly organic waste, as we recycle everything else.

Did you dechlorinate the tap water before you added it? Those 'friendly bacteria' tablets are a waste of money, filter bacteria is aerobic and can be killed very easily, those tablets do nothing really. The only friendly bacteria product I have ever used that actually works is bactinettes.

Those kind of products should only be used in an emergency and not as part of your cleaning routine. Just syphoning out some dirty water (and poop) adn then rinsing the filter sponges in some water from the tank (NEVER tap water) is all you need to do to keep the tank clean. Do not let raw tap water anywhere near the tank or filter, the chlorine will kill all your good bacteria. Also don't overclean as this will kill good bacteria. Around 25-30% of the water is all you need to take out and you shouldn't remove the fish from the tank. If this isn't enough then your tank is probably overstocked and you either need a bigger tank or fewer fish.

The ammonia level in the tank would have risen as the good bacteria were killed off and this wouldn't have done your fish any good at all.

Another thing to bear in mind is that goldfish grow VERY LARGE (not to the size of their tank, this is an old wives tale) and need a huge tank. 45 litres is not enough long term. If you want to get some new fish consider either some white cloud mountain minnows or get a small heater and get some small tropical fish. They are no harder to look after than goldfish providing you do plenty of research into which fish are best for your tank. I would do this on the internet rather than asking the pet shop as I've been given some shocking advice in the past. Best to check for yourself!

Hope that helps, there's too much info to fit it all into one post

thanks for the info!

yes, I know the tank would soon have been too small for them, but ds won a goldfish at the fair and we havent yet got a garden big enough for a pond. (they were only 2 small fish)
I did de-chlorinate the water, and rinsed the filter sponges in water from the tank. I was a bit slow about hoovering, thats why so much water came out, but we still only replaced about half the water. I dont think there can have been any danger of over cleaning, btw!
you can also get bottles of liquid which claims to be bursting with friendly bacteria that you can pour on the filter, is this more effective than the tablets?

we have our daughter in tears right now and cant sleep because she chose her fish today (we set the tank up fine to how we should of) to find her fish had died early this evening. The gold fish (gold one) was ok and still swimming around fine.

We are baffled how her fish died so quickly when we only got it this afternoon, well 1pm

so sorry to read about yours nighty, that must be very hard after all that time too.

New one today. hoping this one will last longer than a day!

I asked loads of questions though i swear the bloke thought he was on mastermind!

How did you set the tank up? It can take up to 6 weeks for a colony of good bacteria to grow, putting a fish in too soon can expose it to dangerous levels of ammonia. Without a water test it's hard to say but this is likely what happened to the goldfish.

NBN- no, the liquid stuff is a swizz too. I dunno how companies get away with selling stuff like that, it drives me nuts! Other things that could have happened to your fish are pH or nitrate shock. Tap water chemistry can fluctuate quite a lot, I always test mine when I do water changes to make sure it's not going to kill my fish. If you don't have a water test kit then it's worth getting one, you need to be able to test for ammonia, nitrite, nitrate and pH at the very least. The kits are only about £15 and they are easy to use. Not trying to turn it into a science lesson, it does actually make life easier because you'll be able to sort out problems before your fish gets sick

sweet - thank you for the tip. Science lessons and testing the water sounds right up our street!
We might do a test just after changing the tank and another one a few hours later, to see if it's changed?

The fish had been though quite a lot before, including similar tank changes, plus about 3 days in a tiny travelling tank when the first fish first arrived, which is why I cant understand what was different this time.

Our town's water is apparently recycled from sewage, so I guess it has chlorine in. Apparently not all the tap water here does.

t875 - hope your fish is still swimming around today!

A lot of tap water has chlorine (unless you're outside the UK?) but I think the majority has chloramine (chlorine and ammonia) because it's more stable and therefore harder to get rid of- bad news for fish! If you want a full break down of what's in your water there should be a report on your water company's website. still test it for pH and nitrate though because these can vary.

I would test the water in the tank right before you do a water change, make a note of the pH and nitrate. Then check the water that you are going to put in to see if the pH is vastly different. A sudden change is no good for fish. Also the nitrate level of your tap water might be too high, it should be below 40ppm for your fish but the lower the better. It won't ever be zero in the tank because nitrate is the end product of the nitrogen cycle. Sorry if I'm blinding you with science , if you need to know anything else just ask! I'm massively massively geeky about fish

thank you for your help - geeky stuff is just what we need! We are quite a scientific family, so not blinding us with science.
I have already looked on the internet, but cant find whats put in the water. We are in a town on the northern edge of the alps.

I will investigate what we can get for water testing at our local pet shop. How can we kick-start the friendly bacteria if the tablets/liquid is no good - what are bactinettes?

At the moment I havent decided what to do about new fish. Its not certain that we will have a bigger garden soon, so probably wont choose goldfish - it was a fait accompli last time! But Id like to get more fish, if I can be sure that I wont kill them.

You can get water test kits on ebay if you can't get them at your local pet shop. The liquid ones are more accurate and way more fun if you're a science geek cos you get little test tubes

The good bacteria will grow on their own if you add a source of ammonia. You can either use household ammonia or you can just chuck in some fish food. Do this before you add any fish and they won't get exposed to ammonia and nitrite (nitrite poisoning causes hypoxia). This tells you how to do fishless cycling- www.fishkeeping.co.uk/articles_51/fishless-cycling-article.htm

Bactinettes can help speed up the cycle but they aren't essential. They are good for emergencies like when your husband accidentally turns off your filter and nearly kills all your fish but they have a limited shelf life so there's no point buying any unless you desperately need them.

there are plenty of small fish that could live in a 45 litre tank happily but a lot depends on the hardness and pH of your water. Some fish are adapted to soft acidic water and some to hard alkaline water. There are loads of sites that tell you what the requirements are for popular fish so you shouldn't have any trouble researching the right ones.

Thank you very much - I'll do some internet research, but you've pointed me in the right direction now!

Hi all.

Thanks Nighbynight!
Well we still have both fish swimming around ok. The oranda the first fish that survived from the very first 2 we had is going into the corner of the tank and sucking the air at the top, not all the time..I have heard this could be low oxygen in the water. But the second fish is only doing this about 10% of the time than the small gold fish the oranda.

Hubby is going to get a water kit tomorrow.

How are things there Nigh? Have you decided if you are going to replace them?

Thanks, btw. There is great advise here!