Hi there, Thanks alot for getting back to me.
Here's the answers to your questions:
My tank is 24'' by 12'' in size
Filtration is : Elite stingray 10 (A submersible aquarium filter that is ideal for tanks up to 10 gallons (50 L) in volume. Filter is quiet, easy to setup, use, and maintain. Rotational head allows water exhaust to be aimed in any direction. Attaches to the aquarium wall using suction cups mounted on the back of the unit. Pumps up to 200 litres per hour. 220v, 60 Htz, 3.1w operation.
1.5m electrical cord supplied.
Each filter operates with two carbon/zeolite filter cartridges and one foam filter set (supplied).
Approximately 7 x 5.25 x 2.75.
Total number of fish: 7
2 x common goldfish
1 x comet
2 x oranda
1 x minnow -
1 x unsure (similar to a minnow but slightly bigger)
Water test : I don't actually have a test kit, my fish have lived happily for the past ten - fifteen years.
Chemicals: No chemicals added at all.
Water Change: full water change once a month. 20% change every 2 weeks.
The change in behaviour seems to have happened when i added the new fish and Air pump. i can only assume that the new fish were diseased maybe? one of the Minnows died aswell as the (bigger Minnow type mentioned above) withing 2 weeks.
The fish were moved into my new home about 2 months ago.
The symptoms include:
Lack of balance
diving to the bottom of the tank, rubbing it's body on the gravel
some of the fish lay on the bottom of the tank looking lifeless
The big goldfish makes alot of splashing noises as though it's about to jump out of the tank
there are some scales missing (i'm assuming this is caused by the rubbing on the gravel)
Hope you can advise further,
Cheers,
Chris