Fish Dying Within Hours

[Danio3]

Hello everyone I am desperate for help.
Hoping to get some advice on a Fluval Edge 23litre tank I have had the tank for 2 years now and had no problems until the end of November when all my fish died off at first I thought it was a disease but the more I read I think it was over stocked and when the fish were clearly unwell changed to much water and lost the bacteria in my filter.
As I thought it was disease I washed out the tank with diluted vinegar and replaced the gravel and changed all the filter media and at that time thought I understood the nitrogen cycle had water tests done by fish retailer all ok got fish died within hours. Now after 6 weeks of doing fishless cycle still seems that I cant get ammonia down below 1 nirates is less than 10 nitrites is 0 ph is 6.4 the hardness ones are o. My tap water has a reading of 1 for ammonia. Tank water on a test strip the chlorine reading bears no resemblance to the chart. If ammonia levels were my only problem I would expect the fish to last longer than 4 hours have I got a problem with Chlorine ? When I last went to the LFS his test indicated ammonia and he sold me a water treatment to block the ammonia which I added and my ammonia readings went to .5 , got 3 serpae tetras again they all died within 4 hours and I still get these readings I add dechlorinator have done numerous water changes but still not confident of getting more fish.
Today I added water that had sat for 24 hours added the dechlorinater and afer 2 hours tested water it was good no ammonia or nitrates went to LFS they tested water said all ok especially ammonia and nitrites nil readings ph 6.5 so bought 2 Rosy barbs.
They were acclimatised and added to tank at 1.30 and by 6.30 they were struggling to swim and turning over did 30% water change fish still struggling moved into a bowl one gone immediately other sluggish.
When I set up the tank again I did add a heater could it be harming the fish?
Can someone help I have been on other forums but cant quite get a solution to the problem.

 

[RZayneC]

How long are you letting them float in there bags?

How hot is your water? (thermometer not the setting on the heater)

Are you using dechlorinated water?

How many fish are you getting?

If your doing a fish in cycle which it sounds like you are, you need to do a water change almost every day using dechlorinated water(as it will kill your good bacteria from the filter) for 10 weeks!

I recommend you read the section about cycling in my sig.

 

[Prime Ordeal]

You have an unheated, uncycled tank, so it's no real surprise that your (tropical) fish are dying.

If you can, return the fish immediately to the shop. If you can't then you are doing what's known as a fish-in cycle. First get your temperature right with your heater, set it at 25C for now. Then you need to change water daily to keep the toxins down. For this you have to buy a liquid test kit, such as the API master freshwater test kit, so that you can take daily readings of ammonia (and eventually nitrite) and keep those readings below 0.25ppm...always.

 

[RZayneC]

(except nitrAte which can go up to 150/200)

 

[Rummynose]

I'm no expert, but the way I read it is
Ammonia 1 (same as in tap water)
Nitrite 0
Nitrate >10

sounds like a cycled tank to me!
He said there is a new heater and wonders if it is harming the fish.

He added fish and 5 hours later they were dying! So it's not ammonia poisoning.

Could it be a difference in ph? (I've lost recently a few fish due to a ph crash in my tank so maybe I'm a little paranoid) but if the ph at the store is very different from yours you would need to make a much longer acclimation time, the drip method works well!

 

[RZayneC]

Ammonia reading should be 0

Even if there was Ammonia in the water then the filter would change it almost straight away to nitrite then nitrate.

The reason they are dying is unknown possibly due to the water being to cold/hot since they have only just bought a heater...

 

[Rummynose]

Ammonia reading should be 0

Even if there was Ammonia in the water then the filter would change it almost straight away to nitrite then nitrate.

The reason they are dying is unknown possibly due to the water being to cold/hot since they have only just bought a heater...

He added ammo lock, which turned the ammonia to the non harmful ammonium, and the heater was added when he set up the tank in November again. That's how I'm reading it anyways, maybe the op can clarify!

 

[snazy]

It does look to me like a temperature problem as well. Do you have a thermometer? What temperature was it showing when you added the fish?

 

[Gilli]

Check your temperature and make sure that it is keeping a steady heat and not going up and down - might be your heater is not working properly.

Ammonia should be at 0 but you should still be able to add the fish and do daily water changes to keep them alive. When you put them in do the drip bag method of just adding a little of your tank water to the bag at a time to acclimatize them gradually to the change before adding them to the tank.I would go with just a few of the hardier fish like dannios until you see that they are surviving ok and that your water stats get to spot on.

Other than that I would suggest purchasing your fish from a different shop as there may be issues there. Good luck!

 

[Danio3]

Hello all and thank you for replying.
Yes the heater / thermostat is new this time around I have tested it today and it seems to have a lag of 5 degrees c from on to off and is certainly 3 degrees c out thermometer reads less.The temperature when I put the barbs in yesterday was 25 degrees on my thermometer and was only slightly less when they died.I also checked the voltage readings from water I was using to test heater and a earth and got 14 VAC when heater off it was 6 VAC. Previous fish have been Danios that died off within the 4/5 hour mark I thought they were not so temperature crucial. I let the fish acclimatise in the bag in the tank for 45 minutes then dripped in water from the tank then added them to the tank.
Yes I have been using an ammonia lock but different people say use it others don't.
Today I called in at two lfs one independent the other a chain both gave different advice independent says clean out tank and gravel leave out heater and only add dechlorinator and leave for a weeek then add 2 danios.Chain tested water sample I had said ammonia high all other tests just fine ph same as theirs and readings indicate a cycled tank but that I should use ammonia lock in a bucket of water leave for a week test for ammonia and if okay add to tank (I do have a API ammonia test kit but only strips for other tests).So as you can see wildly different advice and not confident in latter.
As of now I have just removed all the water and the gravel along with the heater put back in the old gravel ornaments and plastic plants added water which I dechlorinated and again will take daily reading in the hope it starts as it did 2 years ago.Hope I have answered all the questions on my set up and welcome any further assistance anybody can give. Again thanks for your help.

 

[OldMan47]

You have a very low pH which will mean that you will have a tough time cycling the filter. At 6.4, the cycle typical stalls. The ammo lock would help you tie up ammonia but will become a maintenance issue if you ever fail to replace it on time. When it is exhausted, the fish will suddenly become unprotected from ammonia. With tap water at 1 ppm of ammonia, you are facing much the same dilemma that I do. A water change simply does not remove ammonia effectively. I am fortunate to have a higher pH and significant mineral content to buffer my pH. That means that I have a cycled filter that can handle the ammonia and remove it in short order. One possible solution is a heavily planted tank. If you have lots of thriving plants, they will use nitrogen as a fertilizer and remove the ammonia for you. It would be a good idea to set up that planted tank and make sure the plants are thriving before adding fish to it.

This is a heavy planting.

and another

A half dozen vals is not a heavy planting.

 

[Danio3]

You have a very low pH which will mean that you will have a tough time cycling the filter. At 6.4, the cycle typical stalls. The ammo lock would help you tie up ammonia but will become a maintenance issue if you ever fail to replace it on time. When it is exhausted, the fish will suddenly become unprotected from ammonia. With tap water at 1 ppm of ammonia, you are facing much the same dilemma that I do. A water change simply does not remove ammonia effectively. I am fortunate to have a higher pH and significant mineral content to buffer my pH. That means that I have a cycled filter that can handle the ammonia and remove it in short order. One possible solution is a heavily planted tank. If you have lots of thriving plants, they will use nitrogen as a fertilizer and remove the ammonia for you. It would be a good idea to set up that planted tank and make sure the plants are thriving before adding fish to it.

This is a heavy planting.

and another

A half dozen vals is not a heavy planting.

Thanks for that but as I have such a small tank I don't think heavy planting would be any use to me.
Just checked my water and ph is 6.8 and ammonia .25 so things are improving slightly after water change.

 

[OldMan47]

If your fish can tolerate higher pH, try adding some crushed shells to your filter. It will bring the pH up a bit and add some minerals to your water to make it a bit more stable.

 

[Danio3]

Thanks for info I will get some shells and try that. Can you advise where in filter is best as it is a small square type that has foam ,carbon then biomax it came with the tank.