Help! Cardinal Dead, Possible Lack Of Oxygen?

[Harri]

Hi all,

This is my first ever post to the forum given that I'm new to tropical fish keeping.

So around 6 weeks ago I bought an Aquanano 40. I waited a month before adding any fish. I tested tha water regularly, as I still do, and it was absolutely perfect, so I added its first inhabitants, five cardinal tetras. These little fish did absolutely fine, water still perfect, so 9 days later, I added a pair of German Blue Rams. They were a bit stressed for the first twenty four hours, but settled down, coloured up and yesterday (after five days of being in the tank) laid some eggs. The eggs only lasted until this afternoon as the cardinals found them to be somewhat of a delicacy.

This morning I did a 20% water change. I'd added the new water to a bucket on Thursday, treated with aqua safe, and also bought another heart to warm it up to the same temp as the tank - 80 degrees. I can't think of anymore I could have done to prep the new water in readiness for the change.

So this afternoon, I noticed that the cardinals were gasping at the top of the tank. One of them was suffering more so and I watched it thrashing around for a few minutes before it sank to the bottom and died. It was as though it could only use it's tail fin, the other fins weren't moving. The other cardinals have since lost their colour, one is still gasping at the top and the other three are just on the bottom of the tank (sand) not moving very much. The GBR's have lost colour as well but aren't gasping at the top but heir breathing does seem laboured.

I'm afraid of waking up tomorrow and not having any fish left.

I'm at a loss as to what's going on. I was thinking of going to buy a bubble wall tomorrow to see if that helps the oxygen level - I just hope they're still alive by then.

Any ideas or suggestions would be greatly appreciated.

Thanks

 

[Livewire88]

You say your water is "absolutely perfect" but can you give us more info on what tests you have done and what the results were?

 

[N0body Of The Goat]

Gasping suggests a nitrite spike to me, nitrite prevents the blood from taking up oxygen properly and so fish gasp at the water surface.

Time for a ~95% water change me thinks ASAP!

Did you cycle the tank/filter with ammonia during that month of waiting to add fish?

What are you testing the water with, test strips or a liquid test kit? Strips tend to given inaccurate readings.

 

[Harri]

It's perfect according to the test sticks I'm using - They're the six in one tests.

Zero nitrates/nitrites
General hardness 8
Carbonate hardness 6
Ph 6.8
Chlorine 0

Thanks for getting back to me. Any advice much appreciated!

 

[brian1]

Just wondered if the bucket had been used for anything else, without you knowing........

 

[Harri]

No, brand new bucket only used for water change. I have 12 litres of conditioned, heated water in it at the moment. Should I do a water change tonight?

 

[Jay1983]

ammonia results!!??

your water is also quite hard for rams and cardinals

 

[Harri]

I don't have any of my ammonia testing kit left. I'm assuming that I'd see a spike in nitrites if it was high? Feel free to correct me...

 

[Jay1983]

as said before the symptoms do point more to nitrite, but ammonia can effect the gills to which could cause the gasping. Either way a big water change would help. I'd be doing as big a water change as I could everyday untill the fish seem happy again. One thing I would suggest is to invest in a liquid based test kick such as the API master kit link. If you can afford it that is

 

[Harri]

Thanks for the advice!

In the time since my last post, I've taken out 75% of the water. I had 12 litres of conditioned, heated water to put back in but I was wondering whether I should wait for the next lot of 12 litres to come up to temp and keep on doing batches of 12litres (it's as big a bucket as I have) as opposed to just putting water straight from the tap?

I'll be off to buy the liquid testing kit tomorrow morning.

Thanks

 

[Jay1983]

the Aquanano 40 is a great tank I have one myself... do you have a water conditioner, if so just roughly temp match the new water with what your tank temp is... for cardinals and rams have your water temp set to 28C, just roughly match the water, as long as your ph in tank is similar to your tap water, a few degrees change while water changing will not hurt mate.

 

[fluttermoth]

You can add water from the kettle or hot tap to get your new water up to the right temp.

 

[Jay1983]

just a small side note, if your local fish shop offers Reverse osmosis water, may be worth (again if you can afford) investing in getting some of this in and doing a 50/50 mix RO/tap water... which is what I do for my cardinal, ram set up. It will lower your water hardness which both species would appreciate. Bare in mind you'd have to do the change over fairly slowly, start by adding a quarter RO to 3/4 tap water, then a week later up to 50/50... with cardinals and rams a very very well maintained tank is essential, they are quite touchy fish but well worth the effort

 

[Harri]

My temp is at 28c. I've got another 12litres nearly up to 28 now so I'll put that in and then top it up with conditioned tap water at the same temp.

Thanks so much. I'm hoping that when I get up in the morning, they'll all still be alive!

 

[Jay1983]

My temp is at 28c. I've got another 12litres nearly up to 28 now so I'll put that in and then top it up with conditioned tap water at the same temp.

Thanks so much. I'm hoping that when I get up in the morning, they'll all still be alive!

really you don't need it at exactly 28 to add back as long as your tank temp stays above 25 you will be fine, just use your hand as long as it feels warm (not hot) it should be fine, run the cold and hot tap at the same time use the water conditioner... add to tank.

Do you have live plants in your tank?? not only do they look great (they are also very very easy to keep alive, as long as you choose the correct ones.!!) they also help with water maintenance