New to forum - hope someone can help.
I've been keeping fish for 10 years now and never really had any problems. I've had a small quantity of tetras (neon & bleeding heart) in a small 15 inch tank for 4 years but recently the hood light broke and melted the plastic. I used this as an excuse to get a slightly bigger tank and opted for an Aqua One UFO350 (Limited floor space in house). I dutifully set it all up with the undergravel filter, plastic plants and decor, all washed under running water, and ran for a week adding Cycle as per instructions (as I've done before). After a week I added 2 of my Bleeding Heart Tetras from the old tank, using stress coat and taking all the usual precautions, to act as the pioneer fish to help mature the filter. 5 days later both were dead, which I was quite upset about as I'd had them for about 3 years. Water quality is fine, No ammonia yet, PH in limits, temperature stable etc. The second had definite tail fin rot. So I put this down to bad handling when I netted the fish and stress.

I've now added a few Silver Tip tetras as Pioneers, as I hoped the stress would be less by getting them straight from the shop instead of chasing them around my other tank. When I came down this morning, one was already dead, less than 24 hours later. I'm keeping a close eye on the rest.

I'm flumoxed. I've set up 4 tanks in the last 10 years and I've never lost fish during the initial set up stages, and usually my fish live to a ripe old age, and to lose 3 in quick succession tells me it's got to be the new tank, but what I don't know is why. Water quality is good, although it hasn't cycled yet (I have a new fangled ammonia detector inside the tank that changes colour - it still shows safe and an independent conventional test kit confirms it). I want to transfer the rest of my fish so that I can get rid of the old tank, but if I can't even get the filter to mature before my pioneer fish die, then I'm going to have problems.

Can anyone suggest something I'm missing? I'm following the book for setting up. It's always worked in the past, and I'm not used to this feeling of losing fish for no apparent reason.....

Hi Sodbury, welcome to FK

Sorry to hear about your fish most people do a fishless cycle now to prevent this kind of thing from happening. All you need to do is get an old stocking, fill it with fish food and stick it in the new tank for a couple of weeks. That way you won't expose your fish to potentially lethal levels of ammonia.

As for the reason why your fish were dying, how long did you acclimatise them for? Do you have the water test results for both your new tank and old one?

Personally, I would move the 'pioneer' fish back, do a fishless cycle and then transfer the fish over to prevent any more deaths.

Thx for reply. Must admit the fishless cycle you describe is new to me. I've always been advised to run with a couple of hardy fish to set the filter off to a nice start. I haven't been keeping up with the new thoughts to be honest.

When I added the Silver Tips the tank had been running for 4 weeks. I acclimatised them in the bag in the way I always have done (open of course) for about an hour adding a small amount of aquarium water every 15 minutes.

It's now 24 hours since I added them and the rest (3) look poorly now, they're all towards the bottom of the tank and hiding. Ammonia is still reading zero, as does nitrite and my Ph and hardness are good (It's the same water as the old tank), so I don't think they're being poisened.

I'm reluctant to move these couple of fish into the old tank, because they are fresh from the stockist and an unknown quantity. I'm concerned they may spread something to the rest of my healthy fish.

Accepting I may not be running in the tank according to todays methods, it is a method I've used many times with great success, so I'm not sure that's the problem.

I have just noticed though, that one of my decor pieces has developed (overnight) a lump of white fluffy fungus. Could this have something to do with it do you think? I'm wondering if there was something within the decor that wasn't washed out that could have started the problem (It's one of those hollow ones with an airline inlet to give added aeration). I'm thinking of adding some fungus and finrot medication, but not sure if the lack of tank maturity will mean this causes more harm than good.

Fish aren't bred as tough as they used to be, you can't get such good quality now which is one of the reasons fishless cycles are recommended because they are less likely to survive it, and also because it is better for the fish's welfare.

If the fish are new I would leave them in the new tank just in case, but do lots of regular water changes to keep the amm and NO2 levels down and keep your fingers crossed!

No idea what the white fluffy stuff is, I would take it out to be on the safe side

I'm surprised the amm is still reading zero do you have another test kit just to get a second opinion?

I tend to agree about the quality today. Increasing numbers of dead fish in the tanks at stockists these days I've noticed. Not to mention a lack of "quarantine" signs.

I'm going to do the water change (had one planned for this w/e anyway).

Ammonia has never been a major problem in any of my tanks. I've never seen it get higher than 1ppm (admitedly I find the cards hard to read as none of the colours seem to match very well with the actual result!), before it settles down, but then I tend to do regular water changes and after the pioneer fish, never add too many at once. I have a stick on Seachem indicator inside the tank plus I use the Aquarium Pharmacuticals master test kit, both of which agree. I've got an Interpet test kit for ammonia somewhere, so I'll try that as well, see if it's different.

My PH is 7.4, water is quite hard out of the tap (GH 18 deg and KH 10 deg), but as I say it's what I've always used.

Will keep my fingers crossed. If disaster befalls my fish, I'll probably tear down the tank and start from scratch - and I'll try the fishless cycle you suggest.

The hardness and pH shouldn't be too much of an issue unless they have changed suddenly cos most fish now are tank bred and are acclimatised to our water.

Hope your fish make it, let us know how they get on

Sorry for the loss,
Did you use the sponges from your current tank. Tetras dont really make good starter fish for a tank as they can be 'funny'. New aquariums stress all fish full stop. also i wouldent add the neons untill the tank is mature at about 5-6 months to a year. Well since there was fin-rot i would change a some water.
Good luck!!!!
Sean

Thanks FF. Unfortunately have to report remainder of fish have died in the night.

I've dismantled the tank this morning, and I'm going to thoroughly wash it all (again) in case there was something lingering that I missed. I'll also put new gravel in (I had a surplus from original set up luckily). I hope to reassemble by the end of today and start a fishless cycle as described.

Have to admit, I still stand by the method I used as a good one. MarineAqua 5 - i used the standard undergravel filter plate and powerhead that came with the UFO350. Accept what you're saying about tetras (they weren't neons, but bleeding hearts and then silver tips), however I've always found them to be very hardy in the past. It seems that as fishkeeping has become more popular, the stock appears to have become less hardy I guess.

I'm going to learn from this, and I'm not going to give up. I get a lot of pleasure from my tropical fish, so I'll stick with it and let you know what happens.

For the record, the reason I'm keen to get the new tank up and running, is because the hood light unit has failed on my existing set up, and it's a new hood or nothing which I don't think you can get. My existing fish are spending their life in the dark. It's an awkward size so I don't think there are any 3rd party hoods, and I can't leave it open because we have 2 curious cats.

Thanks for the shoulder guys.

Hi Sodbury, sorry about your tetras. Can you not just move the filter or filter media over, then hey presto, one mature filter in a new tank.

That's what I was thinking today. New tank is undergravel, but my old tank has the filter integrated in the hood and has the pump outlet running over first a coarse sponge, then a fine sponge and finally over a wheel sponge (a bit like a water wheel type arrangement). I've rebuilt the new tank, and I'm planning to steal one of the wifes old nylon pop socks to put some food in to do a fishless cycle, but was also thinking of taking one of three sponges out of the old tank to float on the top (I have some replacement ones so can afford to lose one as I'm sure my old tank of 5 years has plenty of bacteria to spare!!), and add some of the water from the old tank which will be rife with the nitrifying bacteria and kick off the cycle without using any of the bottled stuff.

In the meantime I think I may have discovered the cause of my original problem. Our kitchen was recently refitted and new copper pipes fitted. When I filled up the new tank I didn't run the tap for very long and I have a theory that standing water in the pipes may have had copper in it. I understand this is as toxic as ammonia, and may explain why I'm suddenly having problems. When I filled it up again today I let the tap run a couple of minutes before using the water. To test my theory I'd like to test the water for copper - do you know if there is a test kit available??