Hello all, I have been minding 2 goldfish for my friend for over 3 months and one of them has developed black spots on its fins and body and this seems to be spreading quite quickly. This fish seems to be eating normally and swimming around okay, although we have noticed it lurking underneath the ornament in its tank and lying on the floor of the tank which it has never done before. The fish live in a small tank with no filters. The water is changed once a week and we have carried out no tests for pH levels or nitrate etc. There has been no medication, or conditioners added to the water. There seems to be nothing unusual on the fish such as grains of salt etc apart from these unusual black spots...The fish are fed flaked fish food.

please help me if possible, as me and my friend are worried about little goldie.
Thankyou for any help you can offer.

Hi and welcome to the forum

It sounds like he suffered an ammonia burn and the black is the healing of the scales.
I would up the water changing to three times a week and try and at least get an ammonia test kit.

Could you also fill in as much of the box above as you can so that others posting can get a better idea of what he lives in, thanks

Thankyou so much for getting back to me sandy, I've been very worried about Goldie today. I'll try fill out the info I missed from the box.

When I change the water I empty all of it away and just replace it with water from the tap. I don't know the pH levels of the water from the tap and I don't know the size of the tank either, all I can say is that it's a small tank without a filter.

My friend didn't provide me with any weeds for the tank or gravel, would either of these help to improve the quality of the water? Also, I bought oxygen tablets for fish tanks but never put them in as I didn't want to use them without the permission of my friend, would these be useful? Lastly, would I buy a pH and ammonium testing kit from a pet shop?

Sorry for all the questions, this is the first time I've looked after fish and I want to make sure everything is right. Thankyou

Hi Melie

Can you give us the measurements of the tank? That way we can work out how big it is.

Also, without filtration, the biggest problem your friend's fish face is constant poor water. Fish release ammonia via their gills and waste into the water and this is where filtration is so important. The good bacteria that houses itself within the filter media converts harmful ammonia to equally harmful nitrites and then to less harmful nitrates which is a cycled tank.

You could do daily waterchanges - about 80% which should help them and if you can, instead of adding oxygen tablets, would your friend allow you to buy a pump and airstone?

The best guidelines for fish is:

- 2 goldies need at least 10 gallons of water each (single tailed goldies need 20 gal each)

- excellent filtration means good water quality that is kept that way with weekly waterchanges. If the tank is too small for them, even with excellent filtration, the water would need to be changed every second day....

- adding aeration

- checking the water quality with test kits. This will tell you if the water needs to be changed more

I know you're in a difficult position as they're not your fish..... when does your friend get back?

really? well i was watching a pet show and the vet treated a case alot like hers, and he said it was fungus

The tank is a circular tank measuring 25 inches (63.5cm) around and 5 and a half inches (14cm) high.

My friend gets back on the 19th September, so that's still quite a long time... I think she would be reluctant to buy a filter etc as it was a hard job to persuade her to even buy a bigger tank!!

I've noticed that Goldie seems to have lost some weight and she is now quite a bit smaller than the other fish in the tank, after monitoring her eating though she seems to be eating okay and her faeces seem normal too.

I will change the water in the tank more often from now on.