17 replies to this topic

[Anka]

Details as of saturday

Type of fish:
Symptoms:
Other tank mates:
Tank size / capacity: 4x1.5x2 (~330L [~300L actual water])
Type of Food fed: mixed live food (one/twice a week), NLS community food
Feeding frequency/amount: one or twice daily (small amounts) 6 days a week
Substrate: ADA New Amazonia Aquasoil
Type of filtration: 2x eheim 2215
Frequency of filter cleans: not yet (tank been running for ~7 weeks) [rountine clean in another 5 weeks time]
Frequency and % volume of water changes: weekly ~30-40%
Last water change: Sunday 29 April 2012
PH: 6.85
KH: 4 deg
GH: 8 deg
Nitrite: 0ppm
Nitrate: 0ppm (maybe not quite zero)
Ammonia: 0ppm
Phosphate: n/a (can test if important)
Water temp: 24-26 deg
Medications used recently to date: none
Any recent changes..new fish/filters/power outages etc etc: 6x 4-5cm rainbows added Saturday

Hey Guys,

After 4.5 weeks of cycling the tank (using stability control and after testing everything and found to be 0ppm for ammonia, nitrites and tiny nitrates) I bought 6x 3-5cm boesemani and 4x 4cm empire gudgeons last saturday. Within 24 hours 2 of the larger boesemani specimens died. I noticed shortly after putting them in that 2 large and 1 small boesemani were stressed and swimming at the top of the tank. My tank is planted and has a bit of water surface turbulence. I suspected CO2 levels were too high so I placed some airstones in the tank for an hour to bubble the CO2 out (pH went upto 7.1 - a necessary evil). The largest fish kept swimming at the top and then began to do barrel rolls swimming to the top and then falling back down out of control. At this point I tested the ammonia and it was slightly higher than 0.25ppm (it had been zero the day or 2 before, didn't think to test nitrites/nitrates). THe other large fish stayed in the same spot for hours (5cm below the water line) and didn't move at all [except to maintain his position]. These two were dead by morning

Still no idea why - nitrate poisioning/shock? Ammonia poisoning? CO2/Oxygen issues? Something else?

The empire gudgeons were fine. One of the other boesmani (hasn't died yet) mainly swims against the current of the filter outflow. Is this normal?

I then added 6x incisus (4-5cm) on Saturday after testing everything (details above). Everything was fine. Until last night.

Last night the 3rd boesemani (that had been gulping at the top of the water in the first day) started gulping for air at the top again. He was dead by morning. I did a water change yesterday evening btw (water treated using prime [I add prime (for 400L worth of water) prior to adding the water]).

Any help in identifying likely/possible causes would be greatly appreciated. I've done a bit of research but cannot find anything conclusive.

Thanks

[Anka]

anyone?

[Mr_docfish]

If you are adding new fish to a tank and you are using CO2 - you are best to actually do a water change first, then add the fish, then turn the CO2 on, and dont push it too much for the first few days until the new fish get used to the CO2 levels. This is the case for a few varieties of fish - rainbows, discus and rocket barbs in particular among others....
The ammonia would not have been the problem due to the low pH.... until the pH went above 7.0 when the airstones went in.....
Acidosis due to too high a CO2 content in the blood can be deadly. Even if you take them out after they show the effects, it can already have caused internal damage.

Edited by Mr_docfish, 30 April 2012 - 10:30 PM.

[Anka]

Thanks for that Ollie - I'll remember that!

Did you think the 3rd boesemani would have died from that (a week after the problem)? I forgot to mention I did a 30% waterchange after noticing the initial affects (a couple hours after introducing the initial fish).

[Mr_docfish]

I forgot to add this bit...well worth considering....

Prime (sodium metabisulphite) dissociates into bisulphites and sulphur dioxide... the latter being an antioxidant will bind with, and therefore reduce, the oxygen levels in the tank... also, if the bottle has had anaerobic bacteria introduced to it (check for black or dark purple dots in the bottle), it can create hydrogen sulphide - also an issue with fish's respiration... even though you would need a large amount of hydrogen sulphide to be a problem, in combination with other issues, it can complicate things further.

Damage done can show itself up to two weeks later - similar to the effects with nitrite poisoning...

Edited by Mr_docfish, 30 April 2012 - 10:31 PM.

[Anka]

How do I ensure there is enough oxygen?

I don't usually have an airstone, and the water turbulence isn't high. I count on the plants producing oxygen, but like I told you the other day I don't think the water is saturated and oxygen bubbles aren't forming on the plants.

[Mr_docfish]

only real way is to get an O2 meter, or watch your fish

[Anka]

I assume O2 meters are $$$?

I'll stick with watching my fish lol

Edited by Anka, 30 April 2012 - 11:29 PM.

[Bowdy]

Throw an air stone in the tank or run a Venturi off your spray bar.

[Anka]

Will it not bubble the CO2 out though?

[Brett]

This is a small fish volume in a fair sized tank, I doubt O2 levels are going to be an issue unless the fishes gills have been damaged by some other process.

When I first read the post, like Oliver I suspected CO2 toxicity as the most likely problem. Running the numbers gave a CO2 concentration of around 20ppm which didn't seem too bad, but you wouldn't need to be far out with the pH or kH to substantially alter this number and the test kits can be inaccurate at times.

As Oliver suggested, I tend to turn the CO2 off when adding fish, the plants won't miss it for a few days, and gradually increase it again while watching your new additions.

Cheers
Brett

[Anka]

Hi Brett,

Thanks for the help.

If I turn off my CO2 won't my pH rise?

[theonetruepath]

I'm surprised nobody has pulled you up for this part:
'After 4.5 weeks of cycling the tank I added xxx fish'
How exactly did you cycle the tank without fish?

Sounds to me like you cycled it under a very light (or no) load of ammonia. This results in a very light cycle which can handle only a small fish load.

When doing this you should start with sacrificial fish or few fish.

The bacteria has to build up, and it takes another full cycle period for it to build up from 'very light' to a healthy load.

Point 2: After adding fish initially you noticed ammonia levels rather high. This combined with fish dropping dead is a clear indication that the tank is under cycled for the fish load. After this you added still more fish.

Well the good news is that in 6 weeks time your tank will be nicely cycled. The bad news is that all the fish you have added to date can be considered 'sacrificial'. They will either die or be forever weakened by ammonia burn to the gills.

In my experience you have to ramp up fish loading in a new tank. Each ramp is 6 weeks initially dropping to "a few" weeks after a few ramps.

The alternative is massive water changes, often.

[Anka]

The tank is heavily planted. It had decaying plant matter from day one.

The aqua soil should also have given off ammonia initially.

I thought that that would be enough?

.

Edited by Bowdy, 01 May 2012 - 11:30 PM.

[theonetruepath]

It's enough to start a cycle. But it's not enough to establish enough bacteria to handle a heavy fish load. The only way to do that is to have as much ammonia as that number of fish generate, in the tank, to feed that much bacteria for four to six weeks.

This is why you should stock lightly and gradually increment.

After your tank has been established for a long time, it will have a far greater capacity to handle sudden increases in fish stocking levels.

[bigjohnnofish]

bacteria numbers and fish numbers should go hand in hand....

more fish in your tank and you need more bacteria... pretty simple equation... bit like food it / crap out... keep ratio in balance and its all good...

2 gold fish are always good tank cyclers in my opinion...

[Anka]

so many differing and contradicting information all over the place!

aghhhhhh

I'll leave the fish for now and won't add anymore for a couple weeks. How long do you advise?
How do you know once its 100% cycled and safe?

[dazzabozza]

When ammonia and nitrite are 0 and nitrate climbs (might not happen if your plants suck it all up).

All the zeros before adding the fish most likely due to minimal waste and minimal bacteria formed because of it.

Keep an eye on the KH too, if it gets below 2 it could prevent the bacteria from multiplying also. There's a couple of threads about this. NewFish or Donna's threads from memory.

Instead of adding fish you can try increasing your feeds and see if your bacteria can keep up with the load by redoing your tests.


Daz