Why is my tank murky and smelly?

Question

Hi, a few weeks ago we bought a 20 litre tank which we set up a week prior to getting 3 comet goldfish. It has a filter which runs at full capacity constantly and the water is treated.

All started well, I cleaned out the tank and filter after 2 weeks as per the instructions I was given. Since then the water seems to go quite murky and smelly, some days are better than others.

I've taken to cleaning the filter every other day and I'm surprised at how gunky it's getting. Today I gave the tank a good clean out, replaced 80% of the water with treated tap water and gave the gravel a really good clean and rinse. I also scrubbed the couple of ornaments we have.

I'd like to try and prevent the murk returning if I can so I'd appreciate any advice on how to do this. I was a bit concerned that perhaps the tank is too small for 3 goldfish or maybe we're feeding them too much. We feed them a large pinch of flaked food morning and night time which they finish in about 3 minutes.

Hope somebody can help!!!

Answer 1

ur feedin them 2 much and there fish so there gng 2 STINK

Answer 2

The tank is way to small for all those goldfish! Those fish will get a foot long and need 50 gallons for every 2! They are SO messy and c**p a lot, thats why they need a huge filter and a huge tank!!

Answer 3

yes, your tank is WAY to small, and you are feeding them too much. a tiny pinch twice a day is fine.   you picked the dirtiest and therefore one of the most difficult fish to own. sorry to say, but goldfish are pooping machines... i suggest if you cant provide a bigger  and as well as better filtration, that you return the goldfish and instead buy another type of fish.

some hardy but pretty choices:

betta

gourami (opaline gourami are my fave)

guppy

tetra

danios

and the list goes on...

the store wont let you return a used tank or filter, so i suggest getting a diff fish than goldfish, it would be cheaper than buying a whole new setup.

if you only had one goldfish, however, you might be okay...

Answer 4

well, 20 l is wayyyy too small for even one goldfish. 3 commons (feeder) goldfish need ATLEAST 600 L  and 3 fancys need atleast 200 L. goldfish get HUGE and are messy. i hae to be he bearer of bad news bu PLEASE seriously consider upgrading for the fishs sake! goldfish are acualy like one of the WRST beginner fish. oh and if anyone says they grow to the size of their tank, their bodies do but theyre organs keep growing so they live a short, painfull life. plz upgrade!! =]

Answer 5

your filter may not be working properly. either that or it's a cheap one. either way i figure if you replace the filter, like buy one of the best on the market, your problem should be solved. you don't even have to buy a new filter, you can just get a bottom feeder.

Answer 6

well 20 liters is a little bit for 3 gold fish! gold fish are really dirty and p**p alot! they need a bigger place to be in. they grow big and they need alot of space  

Answer 7

get an algae eater! get a few!!and ur filter jst might not works or might be clogged!

Answer 8

goldfish need big tanks or ponds.

The smelly murky tank could be overcrowding, overfeeding, or dead fish in tank.