Very Acidic Aquarium...

[RHiSC]

melbourne/australia

you serious its overstocked? jeez how boring would the tank be with only a couple of fish in there... what is the problem with being overstocked anyway, the fish seem to be going great.

 

[Davo86]

what are you going to do with them once they grow??
I personally couldn't get the video to work so i don't know exactly what fish you have but with the silver sharks for example, they don't have enough tank length to grow into, these should be getting to 13" and be living for an excess of 10 years, this will not happen if they are kept in a 4foot tank

 

[maximinimus]

what are you going to do with them once they grow??
I personally couldn't get the video to work so i don't know exactly what fish you have but with the silver sharks for example, they don't have enough tank length to grow into, these should be getting to 13" and be living for an excess of 10 years, this will not happen if they are kept in a 4foot tank

Here's a couple of captures (sorry about the quality, had to convert the video to a gif as I dont have the needed codec at work):

I was shocked when I saw the video, it looks like the sort of stocking you would expect to see in a sale tank at a LFS

 

[Davo86]

ammonia and nitrite are 0, nitrate is around 15ppm... not sure about hardness.

weekly water change, around 10%.

Well with 10% weekly water changes on that tank the Parameters are going to be Very different to those posted above i can assure you

 

[vinylman]

Just because you have a large tank, it doesn't mean you can (over)fill it with large fish. Whatever filtration you have has to be able to cope with the amount of fish you have. A lot of large fish means a lot of waste and VERY large water changes. The simple fact is that what you have now needs a much bigger tank. The Bala Sharks alone will grow to 12", if not more. If you kept these fish in a group without anything else, you'd be looking at a 6' tank; with all those other fish, you'd need an even larger tank that that. You need to do a LOT of research and reading before choosing fish for any tank. You can keep several decent-sized shoals of smaller fish in a 4 foot tank, it doesn't have to look empty.

 

[rdd1952]

The overstocking is probably the cause of your low pH. Old tank syndrome is caused by high nitrates which push the pH down. The fact that you have an overstocked tank and are doing small water changes puts you in the position to see that happen even though the tank may not be that old. I know you said your nitrates were at 15 but have then been considerably higher at any point?

 

[RHiSC]

nope normally around the 15-20ppm range... everything seems fine and all of the fish are very healthy... the only this is the low PH. also those photos are a bit misleading... if you saw the video you would see that the fish are all bunched up because they think they are getting food.

 

[mike os]

very very overstocked

Ph WILL change with stocking levels as biological processes use chemicals in the water column, and bio-by-products react with chemicals in the water column, ultimately redicing the chemicals required for buffering and leading to low Ph.

in a tank that size with that level of stock you would need to be doing about 75% water change a day to maintain stable ph and other parameters.

Ph that low is not an issue of its self, my rays & discus have been below 4 and breeding, but it always means water changes are potentially lethal as the small amount of buffering added can create very fast,though short lived, Ph changes