What Fish To Start With ?

Hi Billy,

When you were given the tank do you know if it was cycled, the filter needs matured bacteria to be established before you add any fish?

Fish shops very rarely tell you about cycling the filter. All waiting five days will do is tell you if the tank leaks and if your filter and heater work. A lot of shops will say to add some bacteria from a bottle, but most people who have used them find they don't work - and the ones that do only speed things up a bit not do it instantly.

The term cycling comes from the nitrogen cycle:
Fish secrete ammonia. This is toxic to them, it burns their skin and gills making it hard for them to breathe. In a cycled filter, there are bacteria living in the filter which turn this ammonia into nitrite. But nitrite is also toxic; it binds to the fish's blood stopping it absorbing oxygen. In a cycled filter, there is another species of bacteria which turns the nitrite into nitrate. Nitrate is only toxic at very high leels, and we remove it with water changes.
But an uncycled filter does not have any bacteria in it so the fish will suffer firstly from ammonia poisoning, then once the bacteria start to grow and make nitrite, from nitrite poisoning.

Cycling a filter means growing these bacteria. It takes a couple of months for enough bacteria to grow in the filter to support a tankful of fish. The easiest way to do it is to add a source of ammonia to the tank and wait till the bacteria grow, then get fish. There is a 'how to' thread on the way to do this here:
http://www.thinkfish.co.uk/forum/index.php/topic,16.0.html

It is possible to cycle the filter with fish as the source of ammonia but it does take a lot of work keeping these fish alive. It can be done successfully if you start with only a few fish (I would suggest no more than 3 for a 60 litre tank) and are prepared to do daily water changes for a couple of months. Here's the 'how to' thread:
http://www.thinkfish.co.uk/forum/index.php/topic,17.0.html

Can I suggest you read through those two threads and see what's involved with both methods. Then you'll have something to help you decide which to do.


I do realise that your children might not understand why there are no fish in the tank (fishless cycling) but the alternative could well be explaining why the fish have died if you rush to get a lot of fish and don't do the water changes.




The other thing to ask is - what is your tapwater like? If you look on your water company's website, somewhere there should be information on water quality and hardness. You need to know the pH and hardness of your tapwater. They will influence which fish will thrive in your tank and which will struggle.

If your 4 year old would be interested, you could let him 'help' with the water testing (ie watch you do it  ), that could help with the wait.

One advantage to fishless cycling is that because you have to wait to get fish, you do have plenty time to decide on what to get. Go fish window shopping, see what all your local shops sell, go home and google them. That'll help you find out what you like, what will go together, what will fit in your tank and what fish to avoid.
Have you found the community creator on here? It is hidden a bit. Go to 'fish profiles', find a fish you like the looks of in the database, then scroll right down to the bottom of its profile. Fill in your tank details in the boxes and click save. Then you just click on 'add this fish to my tank' for the fish you want, updating the numbers of them for shoaling fish. If you want to save the data you do have to 'join', I just used the log-in data for the main site.
Tip - tetras are under characins, and 'others' covers quite a few types of fish so look there as well.

We are going to a maidenhead aquatics place this afternoon. Our local place we have been going to never seem to have time to talk about our questions and were the ones that said come back in 5 days to test water and start buying fish ! I think i know someone with a fish tank so will try to get some from them . We have already put the plants in do you think we should have waited ? In the info it said to leave plants out.

Ha Ha. We went there expecting to buy a test kit and see if they had some media or to try a friend for some. you obviously know them very well because we left there convinced by them that if we bought 3 cherry barbs or danios we would have no problems. All we need to do is take some water in a jam jar they can test it . They did say only 2 or 3 small fish to start with , then in a few weeks you can add a few more. I think i will try some friends first, hopefully they can help. 

Nearly forgot.

If you manage to find someone with a tank who'll let you have some media, it is safe for them to let you have up to a third of their media, though they should reduce the amount they feed for a couple of days before and after and keep an eye on their water. In theory, if you have a third of their media, you should be able to get a quarter of the fish in their tank immediately. That's what I do if I need to set up a new tank - steal some media from one of my other filters. But because you'll have to transport it to your house, there is a risk of bacteria die-off which is why it's worth checkiing with ammonia to make sure everthing is OK before getting fish.

You can leave the old media in there permanently or repalce it a couple of months after you finally have a fully stocked tank.
And on the subject of media, don't replace it like the instructions will probably say. That's just another money making ploy.

great news today, a friend with their own tank brought a sponge . he is going to come back at weekend to show us how to test water and make sure all ok. so hopefully we can get the first couple of fish soon. 

Since you now have a mature sponge in your filter you need to keep the bacteria alive. Do you have any fish food? If you do, crunch some up and add it to the tank. Do this every day till you get your first fish. It will decompose to make ammonia and keep the bacteria fed. If you don't have any food, get some asap. You'll need it when you get fish so you may as well get it now.


Don't forget, not too many fish to start with, then add more very slowly so the bacteria can keep up. They multpily very slowly so don't rush things.

You need to keep an eye on your ammonia and nitrite levels daily for the next few days. If they stay at zero, you can get more fish in a week. I would suggest getting more danios as they are shoaling fish and will be happier with more of them. Since leopard danios appear to be a variety of zebra danios, you could get either more leopards or zebras, they will be happy in a combined shoal.

If your ammonia and/or nitrite readings show more than zero, you'll need to do water changes to keep them down, then wait a week of zeros before getting more fish.