Tank Cycling Query

Firstly, I'm new to this forum so hello everyone....

I have recently purchased a 180 litre tank. It was second hand, and came with a canister filter (tetratec EX700). The media was all in good condition in the filter, so it was washed through with clean water. We have sponge, ceramic rings, filter floss and a new bag of carbon. The tank was all cleaned out, as was the filter. We have also added a double sponge air driven filter internally.

We intend to have a small group of Discus in here. We went through the process - filling with water, tapsafe, substrate, silk plants, rock, airstone, and left it for four days. Then we added 12 small fish to cycle. 6 Guppies and 6 balloon Mollies. 5 days or so passed, no clouding in the water, fish seemed fine, then on about day 6 the first fish died. Then over the next 5 days or so we were down to just 5 fish. I went to my LFS, and he gave me some tonic salts to add. No deaths now for 3 days, all seems well. I have tested the tank all along for Nitrite and there are no signs at all, not even a hint....the water is crystal clear, no water changes have been made since setup. There was a bit of green algae growth on the glass 11/12 days into cycling which I have cleaned off. Now it's 2 weeks, still no Nitrite in the tank.

I'm a bit confused as to why there have been no traces of nitrite all along, but fish deaths? Could my theory be correct?

The pipes that came with the Tetratec canister filter WEREN'T cleaned out...does this mean that the bacteria has lived inside them and my tank didn't need fully cycling, hence the lack of Nitrites? Are these simply very sensitive fish which would be the reason for them dying?

Any help greatly appreciated.I will try to upload a photo of my tank setup below. Many thanks in advance.

Ammonia comes before nitrite and is even more toxic than nitrite.. you should have not washed anything when you got the tank, the filter was probably already cycled.. but now you are in a fish-in cycling situation. You must get your ammonia reading because over 0.25 ppm will harm fish in the long term. This will probably mean that you should be doing a 80% water change with warm, dechlorinated water right now and possibly 30-50% every day thereafter. Addition of live plants will help ease the cycle. Do try to get your own liquid test kit for ammonia, nitrite, nitrate and pH.

Yes, I know it is a pain, this is exactly why we recommend fish-less cycling with ammonia. Do read the beginners resource centre on here.

Welcome, I'm sure we can teach you a lot about looking after your fish.

p.s. that tank is too small for discus, in my opinion.

Im not sure discus are really a good fish to keep in that tank either, although it is quite tall which is certainly a bonus and you really do need a better knowledge of fish keeping before you venture into keeping discus. They are a lot more sensitive to water changes than most tropical fish.

I would recommend you have a spend a few afternoons having a good read of threads/topics on this forum and get your cycle nailed before you consider more fish.

Best of luck

Hmmm.....I did use my own Nitite test kit. I have a PH test kit too. PH is neutral. I know Ammonia comes before nitrite. I actually went to the local fish shop to buy the ammonia test kit too, but he talked me out of it and said it would be a waste of money. He gave me the Tonic salts to spike the tank with and help the fish. I know that Discus are sensitive to water changes. I was following advice from my LFS regarding cycling, and was also told it would be ok for 4 or 5 Discus. I thought a rough guide was 10 gallons per fish for Discus...therefore 40 UK gallons would have been adequate?

I just thought that there would be nitrite present 2 weeks into cycling, or does it take longer? So water changes are recommended? With regards to nailing the cycling before adding more fish, this is definately what I intend to do. Thanks for the help.

lnrak said:

Hmmm.....I did use my own Nitite test kit. I have a PH test kit too. PH is neutral. I know Ammonia comes before nitrite. I actually went to the local fish shop to buy the ammonia test kit too, but he talked me out of it and said it would be a waste of money. He gave me the Tonic salts to spike the tank with and help the fish. I know that Discus are sensitive to water changes. I was following advice from my LFS regarding cycling, and was also told it would be ok for 4 or 5 Discus. I thought a rough guide was 10 gallons per fish for Discus...therefore 40 UK gallons would have been adequate?

I just thought that there would be nitrite present 2 weeks into cycling, or does it take longer? So water changes are recommended? With regards to nailing the cycling before adding more fish, this is definately what I intend to do. Thanks for the help.

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The bacteria that eat through the ammonia are the ones that produce the nitrite. There is no nitrite because there is nothing consuming the ammonia yet, hence high ammonia and dead fish. Forget what the fish shop told you, get an ammonia testing kit asap and get that water changing started as advised above.

Welcome to the forum by the way .

Will go and get one ASAP. Thank you

Any LFS that talks you out of a testing kit and into buying salts and tonic should be avoid at all costs. As friendly as they might be there not doing you any favours. And agree that tank is not good dicus mate also not a great fish to start with sorry

Thanks for the information. I'll continue to cycle until the tank is perfect, I'm in no rush. I've seen pictures of many tanks this size and smaller with Discus, and they're nice and healthy.

So how much room would I need per Discus (in your opinions) if 10 UK gallons isn't enough? I'll still be putting 4 or 5 Discus in it regardless, as that's what I want. I won't be compromising and getting something else, as I just wouldn't be happy with them. If they appear unhappy, then I'll buy a bigger tank and re-locate it. I intend to spend many hours researching, and as I said I'm certainly in no rush...

Really appreciate the help with regards to the cycling process. Many thanks.

lnrak said:

So how much room would I need per Discus (in your opinions) if 10 UK gallons isn't enough? I'll still be putting 4 or 5 Discus in it regardless, as that's what I want. I won't be compromising and getting something else, as I just wouldn't be happy with them. If they appear unhappy, then I'll buy a bigger tank and re-locate it. I intend to spend many hours researching, and as I said I'm certainly in no rush...

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Fish per volume of water is a bad way to stock.

If I was to keep discus, I would want at least a 6*2*2 ft aquarium, but that would take a nice group of 6-10 fish. The problem is not the volume, but the space the fish require to swim and to get away from a breeding pair potentially.

You would need a lot of practical experience to be able to tell if your fish is not happy and even more to tell if it is becoming stunted due to the tank size. If you are prepared to wait years for that experience.. you're more patient than I have ever been! The alternative, is to use our collective experience to guide you.

Kitty Kat said:

lnrak said:

So how much room would I need per Discus (in your opinions) if 10 UK gallons isn't enough? I'll still be putting 4 or 5 Discus in it regardless, as that's what I want. I won't be compromising and getting something else, as I just wouldn't be happy with them. If they appear unhappy, then I'll buy a bigger tank and re-locate it. I intend to spend many hours researching, and as I said I'm certainly in no rush...

Click to expand...

Fish per volume of water is a bad way to stock.

If I was to keep discus, I would want at least a 6*2*2 ft aquarium, but that would take a nice group of 6-10 fish. The problem is not the volume, but the space the fish require to swim and to get away from a breeding pair potentially.

You would need a lot of practical experience to be able to tell if your fish is not happy and even more to tell if it is becoming stunted due to the tank size. If you are prepared to wait years for that experience.. you're more patient than I have ever been! The alternative, is to use our collective experience to guide you.

Click to expand...

That's a big tank!! I know Discus thrive in shoals, but you're not seriously telling me that everyone who succesfully keeps Discus has a tank that big? Ideally, I'd also like a tank that big, but it isn't going to happen anytime soon!

I really do appreciate the collective advice given - water changes will be made today, and an ammonia test kit will be bought tomorrow. I know volume isn't the perfect way to stock, but surely it's a good rough guide.

And no, I'm not THAT patient! There must be some guides somewhere on the net that will give you a rough idea or an average growth rate of healthy Discus. Also feeding habits, behaviour, colour and obviously condition are sure tell tale signs of healthy fish. I think that's what most people would base healthy fish on anyway.

Once again, all your help is appreciated.

Please take this as intened, Some people that keep fish like the look of them and get them as thats what they like others refuse to get them as they know its not in the fish's best interest.
As a example there are certain fish that i love the need a ph of 7.5 i know full well my water settles at 6.5, now alot of keepers say the fish will be fine and get used to it but they recomemend 7.5 for a reason.
It down to each of us to make the choice and we shouldt judge each other

That's a fair comment agreed

lnrak said:

Kitty Kat said:

lnrak said:

So how much room would I need per Discus (in your opinions) if 10 UK gallons isn't enough? I'll still be putting 4 or 5 Discus in it regardless, as that's what I want. I won't be compromising and getting something else, as I just wouldn't be happy with them. If they appear unhappy, then I'll buy a bigger tank and re-locate it. I intend to spend many hours researching, and as I said I'm certainly in no rush...

Click to expand...

If I was to keep discus, I would want at least a 6*2*2 ft aquarium, but that would take a nice group of 6-10 fish. The problem is not the volume, but the space the fish require to swim and to get away from a breeding pair potentially.

Click to expand...

That's a big tank!! I know Discus thrive in shoals, but you're not seriously telling me that everyone who succesfully keeps Discus has a tank that big? Ideally, I'd also like a tank that big, but it isn't going to happen anytime soon!

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Surviving and thriving are two different things. I have seen fully grown, adult discus which I would never be able to put into a small tank with a clear continence. A lot of people do keep them in conditions which I, personally, think are poor.

lnrak said:

Kitty Kat said:

Fish per volume of water is a bad way to stock.

Click to expand...

I know volume isn't the perfect way to stock, but surely it's a good rough guide.

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The biggest problem is that it doesn't take into account the swimming space required by the individual fish.

lnrak said:

Kitty Kat said:

You would need a lot of practical experience to be able to tell if your fish is not happy and even more to tell if it is becoming stunted due to the tank size. If you are prepared to wait years for that experience.. you're more patient than I have ever been! The alternative, is to use our collective experience to guide you.

Click to expand...

And no, I'm not THAT patient! There must be some guides somewhere on the net that will give you a rough idea or an average growth rate of healthy Discus. Also feeding habits, behaviour, colour and obviously condition are sure tell tale signs of healthy fish. I think that's what most people would base healthy fish on anyway.

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I have seen 10" discus often, and have seen 12" ones occasionally. But online? I have seen normally reputable sources give adult sizes as 6-8" even.

BigbruiserAl said:

Please take this as intened, Some people that keep fish like the look of them and get them as thats what they like others refuse to get them as they know its not in the fish's best interest
[...]
It down to each of us to make the choice and we shouldt judge each other

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+1, there is a reason why I have never bought a discus, even though I have wanted them for 10+ years. For the same reason, I had to find new homes for fish I "rescued". Even for my green terror who came with a tank I bought and the whole household got attached to.

If you want a certain fish, there are products out there and ways to alter water chemistry, which I'm sure you're aware of. If you wanted a certain fish, then if you have the money for the equipment, and the knowledge, then it IS possible to keep that fish.......and for it to thrive. There is a way around most things these days.

That's my personal opinion

Right - update......did a 1/3 rd water change last night, and went out this morning for an ammonia test kit. Results - Ammonia zero, nitrite zero. It's been set up for 15 days. As I said before though, if there was still bacteria in the pipes of the canister filter, would that be enough to keep the tank up and running when I set it up? Maybe the fish were a bad bunch from a poor shipment?

Surely if it was ammonia poisoning, then even after a 1/3 rd water change there would still be some signs if the levels were high to start with? I'm a little confused. Both tests are showing absolute zero. thanks in advance, any info positive or negative is welcomed and appreciated.

Just to add, I went to a different fish shop this morning, and I was advised NEVER to do a fishless cycle. It takes too long and isn't anywhere near as good. They don't stock Ammonia. That's what I was told.