Fish Dying All The Time....help!

[alexpb22]

Hey folks,

I'm just looking for some advice.

I set up my tank about 6montns ago after doing a fishless cycle. The tank has been great and for a while everything seemed to be doing well.

Then after about three months I started losing fish and this seemed to tie in with after doing a water change. At first I lost gradually the five chain loaches that I introduced, this happened one at a time over about four weeks. I have one left and for some reason he is still going strong!?!

I then lost one of my dwarf neon rainbowfish along with one of my honey gouramis who had been doing really well.

Then the following week lost another rainbowfish after doing a water change and then the week after another honey gourami.

I then bought two more honey gouramis to replace the lost ones and also a pleco for the algae. The week after, my last original honey gouramis died. A few days later my pleco vanished and I know he has also died as haven't seen him now for four days. Then yesterday another honey gourami disappeared (presumably dead) and I think one of my new ones has also disappeared today (presumed dead).

I must say that none of these fish exhibited any kind of illness, infection or fungus on them and I'm normally really good at spotting when a fish is on the way out several days/week before they go.

A couple of the earlier fish I knew were going to eventually die becaus of how they were behaving but the recent ones have been doing really well and then just disappearing (generally hiding somewhere to die).

I can't tell if it's something seriously wrong with my setup or whether they just were weak fish due to breeding/shops etc. All I know now is that I can't keep replacing them at the rate that they're going as it's getting expensive and if this is the way forward then I probably should pack it all up.

All my test readings are always good in that no ammonia or nitrite ever shows up. I do have a highish 30ppm level of nitrate but unfortunately that is already present in my tap water but it doesn't seem to bother the fish in my other tank who have all been there for many months into years.

Can anyone suggest what it could be or shed any light on it? I really love my tank and always work hard to try and keep it running perfectly but these stats really aren't great.

I look forward to reading your comments.

By the way, the fish are all bought from a very reputable shop in North London. I do have a brown algae (diatoms) problem but don't believe that this should cause any real problems.

 

[Meeresstille]

That's strange. Initially, while reading your post I was thinking maybe a pH problem. Still worth checking, if your tank's pH differs greatly from your tap water's pH that could cause problems. But you say your other tanks are running fine, so I'm thinking it must be tank specific. 
 
How big is your tank, how many fish and what species are you stocking it with?
Decor might cause problems if it is leaking toxins or paint into the water. I've read threads where people had to remove decor because of it, could also do an online search if any of your decor might already have shown to cause problems.
 
Plants that are not aquatic can sometimes find their way into the LFS and into our tanks. These might introduce toxins into the tank from fertilizers not intended for aquariums.

 

[Byron]

More data will be needed before we can pin this down.  First, are you using a water conditioner at water changes, and if yes, which one?  Are any other substances/chemicals being added to the tank?  How often are water changes, and what volume of the tank?  Filter cleaning?  What fish are in the tank, and numbers?  What is the GH and pH and temperature?  You mention another tank, so I assume you have two and these deaths are only in the one; are you doing anything different between the two tanks (water changes, substances, etc)?
 
Byron.

 

[alexpb22]

Thanks for your replies so far.

Let me try and answer some of your questions:

The tank ph is the same as my tap water. I do live in a hard water area and the ph is fairly high at about 7.6/7.8, having said that it's the same in my other tank although the other one has been running far longer.

The tank is 128litres and has Dwarf Neon Rainbowfish and Honey Gourami plus one chain loach.
I don't have any real plants in there but the only plants I have are the Sydeco ones and one Fluval plant. I also have driftwood.

I do use water conditioners for changes, usually Aquatan sera but the last one I did was with Stress Coat Plus.

I do a water change weekly or every two weeks and usually about 20% to 30%. I have cleaned the filter once since I started up the tank and I did this in the aquarium water.

At the moment I have three honey gourami and seven dwarf neon rainbowfish. I did have two more honey gourami and have never had any issues with behaviour or aggression. All the neons are male and all the gouramis are female. Temperature is 26 degrees.

Regarding the water changes with the other tank, I do exactly the same with both and at the same time. The other tank has had zero problems but may be because it's just stocked with tetras and guppies. Had a few deaths over last two years but only after having the fish for a long time.


I think I have decided to stop restocking this tank and as I have hard water may turn it into a dwarf cichlid tank but as they are more expensive don't want them to die. Anyway need to sort this first as it's a lovely tank and the fish do seem really happy in there when they're well. Neons do all sorta of displaying and swimming in shoals, they really are a great fish and my honeys just potter about doing their own thing.

 

[Byron]

I don't see anything here that stands out.  The fact that this is confined to one tank, and assuming you are doing similar water changes in the other, would suggest it is something in this tank.  Here it could be a toxin leeching from the wood [I had this back in 1997] or the fake plants, or a disease internal to the fish which presumably would be introduced with new fish but this appears to have started after 3 months and not after new acquisitions.  Something could still have come in with the original fish of course; internal protozoan can turn up weeks and even months later, and sometimes not in the host fish.
 
I would suggest more frequent water changes, no less than weekly, and somewhere between 1/3 to 1/2 the tank volume.  This applies to all aquaria with fish.  The benefits of a water change cannot be overstated, so it won't hurt and will help.  Nitrates at 30 ppm are high, and if I were you I would look at dealing with this.  As they are in the source water, there are other methods to handle them.  Many of our fish are affected by nitrate above 20 ppm long-term.  I'm not suggesting this is the cause by any means, but it will add to the fish's difficulties.  And loaches are very sensitive fish to begin with.
 
Byron.

 

[alexpb22]

I am going to up my water changes in the amount and make sure that they are at the least weekly. My nitrates are high assuming that the test kit is correct and from what I have heard it could be completely wrong. Not sure what I can do about the nitrates. RO water is completely out as that will never work for me. Any other suggestions?

Since writing this, I have discovered one of my newest honey gourami lying on the bottom of the tank. This one went in about two weeks ago. I noticed two days ago that things weren't right and I now know I was correct. Weirdly though I still have five of the original dwarf neons in the tank so not sure why these guys have managed to hang on.

 

[Meeresstille]

Would you be willing to take out everything in the tank and see if you can keep fish from dying when the tank is bare?
My son had to do this for one of his tanks because every fish he added died within 2-7 days. Turned out it was the gasses of a rotting dead palm tree in that room that introduced toxins into the tank. At least that's the only explanation that makes sense since he tried everything and only after removing the plant did he have success stocking that tank.
 
To remove Nitrates you could either use live plants in the tank or I've heard of people leaving potted plants at the top of the tank with their roots in the tank water. Spider plants are good for this idea. 

 

[Gruntle]

Are both tanks in the same room? I ask in case there's something in the room that's causing the problem (like a palm tree as mentioned above, or perfume/deodorant/insect spray). If so, do both tanks have lids?
 
It sounds like a queer situation so any information could be helpful. I feel like a detective or something...

 

[alexpb22]

Would you be willing to take out everything in the tank and see if you can keep fish from dying when the tank bare?

I could do but my tank is quite heavily planted so would be reluctant as it may upset the balance plus would the empty space stress the fish out?

I don't have any plants in the room but I just remembered that sometimes I use a room diffuser with scented oils. It could be this that is getting into the tank!?! I haven't used it for a week though and have been losing fish in the last few days. When I got the tank I was totally aware that I shouldn't use anything like that in the same room but I guess I forgot all about it and as the fish were doing well didn't think any more about it. However I've still got several of the original fish so surely if the water was getting toxins in they wouldn't still be alive?

The tanks are in adjacent rooms but the doors are usually open so share the same air and are only metres from each other. Both tanks do have lids though. I think I will try to get some plants in just to consume the nitrates.

I have already decided that I won't be replacing these fish anymore. Once they have gone I may set up a dwarf cichlid tank esp as I live in a hard water area with higher ph. It may make sense in the long run but need to do far more research on cichlids first.

 

[alexpb22]

Well I have lost another honey gourami so all I have left now is one honey and seven dwarf neon rainbows. I've decided not to keep replacing these as I'm just wasting money now. Shame as I spent a lot of time trying to get this right and can't seem to be able to crack it.

Not sure what to do once the rest go but the neons seem pretty happy as does the other honey gourami. Maybe I should just get other types of rainbows since they seem to quite like it.

Incidentally I have quite a lot of black brush algae growing on the wood and also diatoms. Could this contribute to the death of fish? As far as I can tell , prob not.

 

[Byron]

Incidentally I have quite a lot of black brush algae growing on the wood and also diatoms. Could this contribute to the death of fish? As far as I can tell , prob not
 

.
Not directly, no.  But algae issues sometimes occur due to problems that may be connected, though not too likely.
 
Algae occurs in the presence of light and nutrients, and obviously this condition exists in any aquarium with live fish that are being fed.  Live plants can use the light and nutrients when they are balanced, but without live plants (as you mentioned previously) expect algae.  It is useful as like the higher plants, algae will use the nutrients to produce oxygen, though less compared to higher plants.  But algae is natural.  Keep the glass inside clean; beyond that, it is up to you how much algae you want.  But in the absence of plants, algae can only be controlled by light (intensity and duration both factor in) and removing nutrients via water changes with substrate vacuuming.
 
Diatoms are due to low light, silicates (certain minerals), and usually seen in new setups.  Though in the absence of plants they may occur anytime.  Are you certain this is diatoms, and not a form of brush algae  If it easily comes off with your fingers, it is diatoms; otherwise, a type of brush algae.
 
Byron.