Fish Dying

[macbrown]

Hi,

I originally posted this in New section, but someone suggested it might be more relevant here.

Back in March my wife decided to buy some fish for the kids. Under the recommendation of the Aquarium shop, she bought 6 Zebra Danios and 6 Mountain Minnows in a 21 litre tank. They're all bored of the fish now and as normally happens I'm left looking after them.

I do a 1/5th water change every week, dechlorinate the fresh water beforehand overnight and add cycle once a week (as I was told).

In the last month I have had 2 of the minnows die. They were struggling to swim in any direction and looked to me like maybe their swim bladder had gone (if that is even possible).

Today, one of the larger danios has died. I assumed it was pregnant as it's belly was large (had been for a while), then two days ago it had bright red marks on its belly and would swim very rapidly around the tank and then rest on the bottom not moving.

From reading on here it looks to me like it oculd be Dropsy, Columnis or Gill disease.

If anyone could point me in the right direction before the rest start dyiing. Thanks

 

[GuppyGoddess]

That seems like too many fish for a 21 liter tank. Isn't that the equivilant of a 5 gallon tank? In my 5.5 gallon I only keep one 2.5" long fish. Rule is 1" of fish per gallon. Seems like you have more than double that.

Have you checked the ammonia levels? Try an API test and then if the levels are high, increase the amount of water being changed out.

 

[shelaghfishface]

any chance of you getting a photo?? last thing you want is to be treating the tank for the wrong ailment

 

[macbrown]

A photo of the dead fish? Already in the bin I'm afraid. There are 9 fish left in the tank, looks like plenty of room to me, or is more a case of the waste they produce (GuppyGoddess mentioning 1" rule)?

I'll go and buy a Water Testing Kit at the weekend. What should I be looking for?

 

[WILDER]

Immediate water change and increase aeration.
Get water tested.

I would take the danio back as they need at least 10 gal tanks.

Swim bladder and septicemia can be caused by bad water quality.

Api master liquid test kit.
It has ammonia, nitrite, nitrate, and ph test kits.

 

[macbrown]

How much water change?

 

[WILDER]

I would remove half of the tank water.

 

[GuppyGoddess]

I would take the danio back as they need at least 10 gal tanks.

Is it ethical to take back a fish when you know the tank it's from is possibly harboring disease?

 

[WILDER]

The tanks overstocked that why there is desease.
I meant when symtoms have cleared up.

 

[macbrown]

Thanks, will do.

 

[macbrown]

Right, I have done the water change and tested the water.

The only one that was looking slightly off is the ph level, which looks to be between 6.4 to 6.8, a bit low but not too bad?

I went to the shop where we bought all the stuff from and they suggested that it is probably too many fish (as some of you have). Funny, it was them that told us we could have up to 12 in it and the sold us the fish. The chap today said eight is probably still too many and that 6 would probably be a safe mximum. Any other help or opinions would be appreciated, but thanks for your inputs so far.

Cheers

 

[WILDER]

Research the fish before you buy.

Tetra are out of the question as with being a shoaling fish they need room to move.
The minnows are fine in that tank size I think.

Maybe just keep 6 minnows.