Dead Fish

[MrsH]

I wonder if someone can give me some advice as I'm fairly new to this and had a big death disaster this weekend.

I have a tropical tank that I set up last year and all was going ok until a few months ago, we had the occasional death but nothing more. I recently went away for 3 weeks. The fish were looked after by a combination of slow release food and a friend house sitting for part of it. We lost most of our fish during this time and a couple of fish in the few weeks after. We did have one ruby shark, some rainbow fish, platys and black phantom tetra. We were left with one phantom tetra and the shark. At this point we did water checks and our nitrite/nitrate levels were high and we had some film on the top of the water. I wondered if we were overfeeding and with some water changes and reduced feeding things settled.

This weekend, at least a month after the last death we bought 6 more phantom tetras. We added them by slowly adding our tank water to their water and eventually releasing them. About 4 hours later one of the new fish died. I checked the pH and it was 8.2 so I put in some pH down ( I have since read lots of posts about not using it). The next day practically all of the fish had disappeared. We removed our filer (a stingray design) and found them behind it- either dead or very nearly dead. Currently we are back to the shark which looks fine and 2 phantom tetras- one looks very healthy (i think was the original one), the other looks like its going to die soon- its barely moving and has lost most of its tail and fins are split.

Current water test- pH 8.0 (tap water 7.4-7.6), ammonia 0, nitrites 0, nitrates 20 and the film is back on the water.

So now I'm not sure what caused all the deaths- I assume they didnt all just get trapped behind the filter and then die, although I have just put a semi-permeable thing down the middle of my tank to split the tetras from the filter, and also from the shark as it was chasing them fairly aggressively (more than it used to do with the old fish)

Could my pH being too high have killed all the new fish so quickly? If so what is likely to be making it so high (to be honest it has always been about that level)? and how do i reduce it safely? Should I be doing anything different when getting new fish?

Sorry for the long post but thought it best to give all info now rather than have people need to ask lots more questions.

Thanks

Kirsty

 

[james_fish]

Sounds to me as if the holiday food as destroyed your water quality.
Your pH is also very high. Great for Rainbows but not good, especially for the Tetra's. pH down and that don't work in my experince in order to lower pH in your tank you must add something along the lines of bogwood or peat slugs.

Also if you did not do a water change for 3 weeks this could have caused monumental nitrate levels. Although nitrate is the less poisonous of the 3 main toxins, it can be deadly over a period of time.

Oh, and to the forum.

James.

 

[rdp50734]

If you put the PH down in while the fish were in you probably burnt them with the acid! As far as I know the PH usually drops from the PH of tap water ie from 7.5 down to 7, I suspect you have something increasing your PH be it substrate, rocks or ornaments. The holiday blocks are notorious for polluting the water levels! You filter may have been catching up when you tested it hence the nitrates/nitrites.

 

[MrsH]

Thanks James

The holiday was May/June. Unfortunately yes we couldnt change the water during this time but we have changed the water multiple times since then and I had thought that we had left enough time for things to settle?

Is my current nitrate level posionous? You mention that it can be deadly over a period of time, so this is unlikely to have caused the death of all the new fish in the 24 hours since I added them to the tank?

I had read about bogwood, and we will probably do that but I dont understand why the pH is so high in the first place, and wanted to check that the pH was the likely cause of the deaths or if I had to be worrying about anything else killing the last few.

Rdp50735

Im sorry I dont understand- if I am going to use pH down (I don't plan to anymore) how can I add it without fish? If it was what killed my fish with acid then why would only the new fish die?

If the holiday blocks are so bad what is best to do to feed the fish when we go away (we are new to the area so dont have anyone to feed them for us)

How do I find out what could be increasing the pH? I do have a couple of rocks in there but they are all ones that were bought specifically for the tank, do I need to take them all out?

Thanks again for your help

Kirsty

 

[rdp50734]

Im sorry I dont understand- if I am going to use pH down (I don't plan to anymore) how can I add it without fish? If it was what killed my fish with acid then why would only the new fish die?

You need to add it to the new water in say a bucket, then slowly add it to the tank water. Rather than just putting it in the tank.

If the holiday blocks are so bad what is best to do to feed the fish when we go away (we are new to the area so dont have anyone to feed them for us)

They can be left for a week easily without food or you can buy auto feeder units.

How do I find out what could be increasing the pH? I do have a couple of rocks in there but they are all ones that were bought specifically for the tank, do I need to take them all out?

No you dont need to take them all out. I cant remember how to test the rocks I wil find a link for you in a short while.

Thanks again for your help

Your welcome.

If your fish require a certain set of water parameters, rocks or wood can be useful in attaining these naturally (in other words, without chemicals). For example, many types of rocks, such as Texas Holey Rock and Limestone, serve as a buffer and will raise the pH of your aquarium. Driftwood, on the other hand, will often lower the pH and soften the water.

By far the largest majority of rocks/stones/pebbles whatever are quite safe to put in aquaria.

If a rock/stone/pebble fizzes when you put vinegar on it, that means it is calcareous and will harden your water and maybe raise your pH. That, however, may not be a problem in a rift tank for example.

Avoid pieces that are "heavier than they look like they should be". These are frequently but not always crystalline. Usually indicates it is some kind of metal ore which may poison your tank.

There are a few rock types that are high in organics and often throw a film on the surface - if that happens, take it out. It is usually not dangerous, but can interfere with the gas exchange at the surface.

Tis info was taken from this site if you use the search box it will gives loads of info!

 

[Rainbow67]

Also if you did not do a water change for 3 weeks this could have caused monumental nitrate levels. Although nitrate is the less poisonous of the 3 main toxins, it can be deadly over a period of time.

Oh, and to the forum.

James.

I would somehow doubt 3 weeks of not changing the water would cause nitrate levels to rise THAT much!....certainly not to toxic levels.

 

[Rainbow67]

I wonder if someone can give me some advice as I'm fairly new to this and had a big death disaster this weekend.

Thanks

Kirsty

Hi Kirsty, It's quite difficult to be 100% certain what is causing your fish fatalities, just like computers it could be anyone of a number of things or it might be a combination of things.

You do mention that you had someone feeding your fish when you were away, and that could possibly be the main culpret of your fish deaths.
For example do you know how your friend was feeding the fish?
Perhaps they got into the habit of washing their hands with soap prior to feeding the fish, not aware that any traces of soap or detergent can be highly toxic to the fish.
Perhaps they simply over fed the fish, which lead to tank pollution?.

Your current Ammonia,Nitrite and Nitrate readings are fine and your PH levels doesn't seem to be too high to be causing your fish losses.

The new fish deaths could be more stress related, as well as making sure your tank temperature in the fish bag slowly equalises with your tank temperature. (I float my bag for at least 1 hour before releasing fish into the tank), a good thing to do is add some "stress coat"
to your tank prior to the new fish release this supposedly helps calm the fish somewhat (I used it and it seems to do its job!)
Also with new fish I don't usually put on the aquarium lights for a good 5/6 hours, to allow the newbies to really settle in.
Also pay attention to whether any of your old fish are harassing the new fish, the added stress of this might put them over the edge.
Also keep an eye on your temperature is your heater maintaining a steady safe tempertature (the thermostat may be stuck or the heating element might have gone)



I would also check to see if you have enough water movement in your tank, particuarly at the surface......i.e ideally your filter outletwill be disturbing and agiatating your water at the surface, If you dont' have enough surface agitation this could lower oxygen/gaseous exchange. The film you are seeing on your suface could also be hindering proper gaseous exchange and may actaully be a sympton of not enough surface agitation.
If this is the case try adjusting the postion of your outlet pipe to just below the surface of the water and point it upwards (The more surface agitation the better)
Also consider getting some air stone bubble disks (they are better than standard air stones as they create a bigger water column) (about £5 depending on size) and hook up to an air pump to increase circulation and surface agitation.

Hope this helps.

 

[james_fish]

Also if you did not do a water change for 3 weeks this could have caused monumental nitrate levels. Although nitrate is the less poisonous of the 3 main toxins, it can be deadly over a period of time.

Oh, and to the forum.

James.

I would somehow doubt 3 weeks of not changing the water would cause nitrate levels to rise THAT much!....certainly not to toxic levels.

Depends on the filtration and how much waste the fish were producing, it could be a really small tank for all we know (higher concentrate of nitrates in a small place). Maybe there are no plants either to help with the removal of Nitrates.

Thanks James
Is my current nitrate level posionous? You mention that it can be deadly over a period of time, so this is unlikely to have caused the death of all the new fish in the 24 hours since I added them to the tank?

I was referring to the 3 week build up during the holiday, not the build up during the new batch of Tetras

I had read about bogwood, and we will probably do that but I dont understand why the pH is so high in the first place, and wanted to check that the pH was the likely cause of the deaths or if I had to be worrying about anything else killing the last few.

Your pH could be high due to maybe some rocks? Or maybe your gravel/sand? What are they both?
Also, what pH is your tapwater?

James.

 

[Rainbow67]

Depends on the filtration and how much waste the fish were producing, it could be a really small tank for all we know (higher concentrate of nitrates in a small place). Maybe there are no plants either to help with the removal of Nitrates.
James.

Although it is better to keep nitrate levels at a lower level, many fish in general can tolerate high nitrate levels for an extended period of time, indeed some species seem to adapt a to a high nitrate level tolerance.
Death specifically due to nitrate poisoning is generally rare in aquariums.
My point was though that I doubt that during a 3 week period the nitrate levels would rise so significantly as to cause such dramatic fish death.
More likely suspects would be ammonia/nitrite poisoining, chemicals, soap or other toxins being inadvertantly introduced into the aquarium, or lack of oxgen or poor surface gaseous exchange or even a malfunctioning heater "cooking" the fish.