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AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

Original poster

To think a goldfish does not need a filter?

42 replies

yankeecandle4 · 01/10/2015 18:58

DD's goldfish died last month. We had it approximately 5 years. She has been asking for another one and we went to a large, well known pet shop yesterday to buy one or two.

Asked for assistance, the sales assistant quizzed us as to what size tank, if we were experienced goldfish owners (?!) and if tank was ready. I answered, said that water had been in tank for 3 days as this was what they had previously advised. She then went on to ask if I had used a filter. I used one years ago but didn't feel it made much difference (they need changed every three weeks or so) so last fishy didn't have one.

She said that it is a requirement to buy one and have it working for 3 days before I can buy fish. The cheapest filter was £26. In my embarrassment I pretended to buy one and said I would return in three days for the fish.

AIBU in thinking that one/two goldfish in a 30 litre tank do not need a filter to survive? Is this just this shops way of generating more cash?

OP posts:
nokidshere · 01/10/2015 19:00

Of course they do. They produce large amounts of waste and it should be filtered for their wellbeing the same as any other fish.

HoneyDragon · 01/10/2015 19:03

Goldfish are the messiest of fish, they need a filter, aren't really suited to tanks, and if tanked need huuuuuge ones. 5 years is young for a goldfish.

laffymeal · 01/10/2015 19:04

Yabu. They need a filter. Pet stores are much more responsible about selling people cold water fish these days, not like before when the poor things were stuck in tiny tanks with too many other fish some carrying disease which ended up killing the whole lot.

Micah · 01/10/2015 19:04

Yes they do.

You also need to cycle a tank properly before you put fish in it. Google, or check out the stickies on tropical fish forums. The shop woman is clueless if she thinks a tank with water in for 3 days will have cycled properly.

Filters don't need changed. They colonise with bacteria that break down fish waste and maintain the water quality. Changing the filter will decimate the bacterial population.

Both you and the shop lady need to do some research on keeping fish.

SalemSaberhagen · 01/10/2015 19:05

I've had a goldfish for 15 years and counting, he has never had a filter Blush

ahbollocks · 01/10/2015 19:06

You definitely do :)
There's some brilliant advice on the web,
I clean my filter every two weeks and use stress coat and a water purifier thingy.
My fishies are 15 Shock

hedgehogsdontbite · 01/10/2015 19:07

Of course they need a filter. A goldfish in a tank should live for approximately 30 years. Although 5 years is pretty good for one which has been swimming around in it's own faeces and urine the whole time.

Creak · 01/10/2015 19:11

Yes, they should have a filter.

Whilst people do keep them without (with varying degrees of success), it's a pretty rough life for them to be kept in small, unfiltered tanks and can stunt their growth and shorten their lifespan (or, as less scrupulous pet shops will tell you - 'grow to the size of the tank'!).

Also the filter can take quite a few weeks to biologically mature and won't be effectively breaking the waste down from three days, so you'll need to keep feeding scarce and lots of small partial water changes with dechlorinated water. And please don't get two fish in one go! I would only keep one in that size tank and be ready to move him into something bigger when he grows.

Practical Fishkeeping website has some good articles on doing it all properly and explains it all very well. I used to do it for a living myself, but ended up leaving the profession after a few years of being shouted at over this very issue! I'll sign off now before my nervous twitch kicks in Wink but good luck with your fish OP, and check out the Fishnet forum on here for help too, they're very good in there!

Idefix · 01/10/2015 19:13

They do need a filter, they are hardy and will survive a lot poor conditions. They should live many times longer than 5yrs.
Filters are not expensive if you decide to get a new fishy friend.

Spidertracker · 01/10/2015 19:18

Yes they need a filter and a much bigger tank than you think.
I personally think goldfish should only be kept in ponds, they are relatively big fish.

Original poster
yankeecandle4 · 01/10/2015 19:45

Ok I stand corrected.

I thought a 30 litre tank is rather spacious for 2 goldfish, considering there were about 15 in the same size tank in the pet shop. (they are around 4-5cm)

Obviously our last fish was not swimming around in five years worth of faeces and urine, the tank was cleaned out every week.

The pet shop woman said that the sponge(?) inside the filter (fluval) needed changing every 3 weeks, as did the instructions.

I am glad to see I am not the only incompetent fish keeper Salem

OP posts:
Tippytappytoes · 01/10/2015 19:55

I have 2 goldfish in a 180 litre aquarium. I have had them a very long time and they are big, messy and totally ungrateful for all the natural plants I buy them that they just rip apart. I have a juwel filter which I rotate in new filters (there are 6 all together) every 6 months with regular testing of the water and adjustments. My goldfish are by far the hardest pets I've ever owned. I'm getting tropical next time, easier.

Rinoachicken · 01/10/2015 19:57

The fish in the shop are babies. Fish grow and goldfish grow BIG when given the correct environment to do so.

A fish in a smaller tank won't grow to it full size, if will be stunted and die young. Kind of like if you keep a child in a box.

The natural lifespan for a big standard goldfish is 20 years+ The size is 10inches. There are many varieties of goldfish and so they lifespan/size vary. As a general rule you need 1 gallon of water per 1 inch of the fish's full size.

So that's a 40/45litre tank for one fish. Minimum.

toboldlygo · 01/10/2015 20:00

The ones in the tank at the pet shop are there temporarily though. Standard goldfish are best left to ponds, IMO, as when properly cared for they grow very large and are massive waste producers.

Fancy type goldfish are much more suited to aquariums, with a guideline of about 40l per fish.

Changing filter sponges undoes all the benefits of having a filter - the aim is to cultivate bacteria involved in the nitrogen cycle. The cycling process takes as much as 6-8 weeks, there is no benefit to waiting three days.

Pet shop advice is pretty variable and often wrong, unfortunately - as suggested by others Practical Fishkeeping magazine/forum is a great resource.

Alternatively there are much more suitable, lower maintenance fish available for small tanks. :)

CakeNinja · 01/10/2015 20:02

Blimey, SIL had a goldfish that died at the ripe old age of 23 which she won at a fair in a plastic bag. Had a big glass bowl with gravel and a bridge and toy diver in the bottom.
We thought it kept dying and that she was replacing it over the years just pulling our leg as we presumed they lasted a year or 2 but it seems she wasn't Hmm
No filter for Skunk!

Original poster
yankeecandle4 · 01/10/2015 20:02

My goldfish are by far the hardest pets I've ever owned.

Mmm, maybe we'll get a dog then.

So why do these pet shops sell those little round, plastic tanks with the rim? I was actually told that I could keep 6 fish in my tank, but as a supposedly responsible owner thought I would give them a bit of space.

OP posts:
Original poster
yankeecandle4 · 01/10/2015 20:04

toboldlygo what are the names of the less demanding fish please?

OP posts:
Lilithmoon · 01/10/2015 20:05

I'm glad you have changed your mind OP. Goldfish need a filter and lots of room. The fish in the shop are babies and won't be in the tank for very long. Have you considered a smaller fish eg danio, mountain minnow, they would be ok in a 30 litre of you have a smallish shoal?
My two goldfish are well over 10 years old and I love them :).

Rinoachicken · 01/10/2015 20:05

You can keep things other than goldfish a small tank. Aquatic frogs, snails, shrimp, fish that are smaller than goldfish...

Alisvolatpropiis · 01/10/2015 20:11

I have nothing helpful to add to this thread, only opened out of curiosity. My mind has been slightly blown upon reading that goldfish can live decades!

toboldlygo · 01/10/2015 20:12

As lilith suggests a small group of something like zebra danios or white cloud mountain minnows would be ideal - they would require a small heater (£15 or so, easy to use) and a basic filter. Consider also guppies, mollies, amano shrimp etc.

A solitary male betta splendens/siamese fighting fish could also work with a little research.

Micah · 01/10/2015 20:16

Also fish shop tanks have massive, industrial filter systems, or should do. Water is constantly being extracted, filtered and returned.

Or all the fish would die pretty quickly.

Pet shops sell stuff for money. Most pet shop staff know nothing about fish.

Goldfish can live into their 30's and 40's if properly cared for.

Put a couple of gerbils in the tank instead. Far easier to keep than fish.

Rinoachicken · 01/10/2015 20:19

Many danio species can live in cold water = no heater required.

Just google 'cold water aquarium fish' and take a look - just make sure you check how big it will grow as an adult!

TreeSparrow · 01/10/2015 20:19

Goldfish are be far the most abused pets. 30 litres is far too small for even one of the smallest fancy goldfish. They need a filter to process the ammonia produced from their waste. Not having one means you are poisoning the fish. Bacteria live in the filter and convert ammonia to nitrite, and then nitrite to nitrate (which is less toxic and is removed by plants and water changes).

3 days water sat in a tank won't do a bloody thing. The tank needs cycling with a filter and ammonia being added BEFORE you even consider stocking with fish. Look up the nitrate cycle, Google "fishless cycling" and you'll see what's needed. It'll take two or three weeks and is easy if you follow the instructions and have appropriate liquid test kits.

You can get a few White Cloud Mountain Minnows for the 30 litre tank but forget goldfish. It's far too small.

Once cycled and stocked you'll need to change 50% of the water each week and replace it with dechlorinated fresh water. The filter media never needs replacing (that's a con) and should only be rinsed through with old tank water (not under the tap or you will kill your cycle).

DontOpenDeadInside · 01/10/2015 20:21

Add a heater and get some harlequin rasboras and some cory catfish. I reckon 4/5 of each in a 30 litre. But please look into the fishless cycle to get the tank ready. Also do you know how to acclimate them? Its not a case of floating the bag for 20 minutes then chucking them in. You have to add a bit tank water to the bag every 5 minutes or so for up to an hour (a ph testing kit is a must) I've got a 160 litre tropical tank so if you need any help/advice just ask :)