There's always shed loads of topics like this in the beginner forum so thought it would be a good idea to have a pinned topic on this page telling you what to do.
I'll kick it off if anyone's got any comments/suggestions/additions post them up
So, you've been lusting after a fish tank for ages now and finally took the plunge and got one, the guys at the fish store said to just get some hardy fish to start it off and you've done so. Now everything's dying and going wrong, so here's what's happened and what you should do now.
Firstly, cycling. You'll hear this term bandied around loads, people will ask how you cycled your tank and your water stats, this is the basics.
The absolute first thing you should buy when your keeping fish is a water test kit. I recommend the API Fresh Water Master Test Kit, they're readily available (in the UK), fairly cheap, easy to use and quite accurate (lots of test kits are awful!)
The main things you'll need to test for are pH, ammonia, nitrite and nitrate. This gives you an indication of the health of your tank it's mostly related to the nitrogen cycle often refered to as cycling.
Your fish create ammonia in their waste, this is toxic so it must be removed from the water, this is what your filter is for, there are nitrifying bacteria living in there who convert the ammonia into nitrite (also toxic) then another species of nitrifying bacteria who convert the nitrite to nitrate which is much safer, you keep this at a manageable level through doing water changes every week.
The main problem with new fishtanks is that the filter's don't come with the bacteria you need. They can't live out of water in the sponge on the shelf in the fish store, however they are all around us, and will relish the opportunity to grow and develop when they find a nice safe home (your filter) and a source of food (fishy waste). The problem starts because when you add fish to your tank you will have a very very small amount of bacteria, they take a while to grow and multiply to the point where they can eat all the waste from your fish, so for the first few weeks of putting fish in the tank the bacteria are growing and will struggle to keep up, so you get toxic levels of ammonia and nitrite in your tank, this can lead to death or disease.
In the past this was always countered by putting in some very hardy fish at first and hoping that they would survive the toxic levels, then when the bacteria had built up after a few weeks you could add more sensitive fish. However this really wasn't very fair on the poor fish who had to start the tank off, I dread to think how many will have died.
Since the advent of the internet new technique called fishless cycling has developed and is now becoming widley used, this is where you add pure ammonia to the tank to grow the bacteria on until they are at a point they can handle the fishes waste, and then you add your fish when it's safe for them. This is detailed in a pinned topic here, have a read.
Your pH will be largley dependant on the area you live in, however there are a number of factors that can affect it, certain substrates, CO2, bogwood and many more can all have an effect on it. For the process of cycling ideally your pH should be above 5, the bacteria that grow in such acidic water are different and may take longer to develop, there are also very few fish that will be comfortable in water any more acidic than this. Different fish have different pH requirements so look into those for the fish you want to keep and check it against yours. There are ways of adjusting pH however this can be very tricky and a fluctuating pH is much worse than a stable one that's slightly higher/lower than the optimum for your fish. In the vast majority of cases it's easier to tailor what fish you select to the pH of your tank.
So that should tell you why the first thing you need is a test kit. If you don't know what level of ammonia, nitrite, or nitrate you have in your tank, you don't know if you have enough bacteria to keep the tank going or if you need to do anything else.
OK So you already have fish, if it is at all possible you should return these fish to the store and then do a fishless cycle. I know you may be attached to your fish and might not want to, so you can keep them if you like, however you must be prepared to accept that some of these fish may die over the next few weeks, you will need to do a lot of hard work and research to get through this. If at all possible I would recommend a fishless cycle.
Keeping your fish? Alright, the single best thing you can do for your fish is to get some mature filter media from a healthy tank and put it in your filter. This will contain all the bacteria they need to survive and will take a lot of work out of it. There's a pinned topic here with details of members who are willing to donate media, or you can ask friends with tanks or the fish shop. Remember if you get some you must be careful transporting it, you should keep it in tank water and get it into your filter within 12 hours. If you do this you should still follow the instructions below, it'll just be easier and quicker for you.
If you can't get any mature media then you're going to have to work hard now. Firstly you need to look at what fish you have in the tank, you actually need to have a reasonable amount of fish to get your cycle going, I recommend about a quarter of the total stocking for the tank. The recommended stocking level is 1" of fish per US gallon of water. So if you have a 20 gallon tank, you should eventually aim for 20" of fish (not 1 20" fish, but 20" total combined from many small fish).To cycle the tank you need a quarter of this so 5" of fish. Look up what fish you have, check what size they get to, add it all up and it should come to a quarter of the size of your tank is US gallons. If your at all confused start your own topic and post what fish you have and the size of your tank and we'll help.
Once you've got the number of fish sorted out you need to test your water for pH, ammonia, nitrite and nitrate. Keep a log of the date you took the reading and what results you got. Post it up for us to look at if you get confused. You will almost definitely get a reading for ammonia, possibly get one for nitrite and possibly for nitrate depending how long the tank has been running and what your tap water contains.
You can expect your results for ammonia to go up then down while the others stay relatively low, then when ammonia has almost dropped to 0 nitrite will start to rise and then fall, and nitrate will start creeping up. When ammonia and nitrite have dropped to 0 then you have a cycled filter.
So now every single day you should check your readings, if you get a reading for ammonia or nitrite that isn't 0 you should carry out a 20% water change. This will most likely be every day for a few weeks; it can even take months in some cases. If you get some mature media you may find it's done in a few days.
When you do water changes you should also use a siphon to vac the substrate and pick up any uneaten food or fishy poo. However don't be too thorough as some of the bacteria you need will live in your substrate and you don't want to kill them off. Make sure you add dechlorinator to the water you put into the tank.
This will go on for a couple of weeks, it will be boring and hard work, but sadly it has to be done, doing it will save your fish.
If you see any signs of distress or illness use this form to post in the emergency section to get advice on medication and treatment. Tell them that you are aware you should have fishless cycled but you are now carefully cycling with fish. Some medications can stop your cycle and will only make things worse in the long run so it's very important to let people know that you are cycling with fish.
Now eventually your readings for ammonia and nitrite will reach 0 and you can stop doing daily water changes, hooray!! You should now cut back to 25% water changes once a week. Now remember your filter is cycled, but it is only able to cope with the amount of waste your current fish produce, if you just get a whole load more the filter won't cope and you'll have to go through this all over again. From now on you should add fish very gradually, a couple at a time then keep testing the water, you may see a mini cycle in which case do your water changes again until it's finished, then leave the tank a week or so and add some more fish. Very gradually over a few months your filter bacteria will build up and you'll be able to finish stocking your tank.
And finally if your at all confused about whats going on it's best to start your own thread, make sure you include details of your tank size, fish you have in it and water stats and we'll do the best we can to help.
Really good advice, cant believe it took so long for someone to reply! Thanks! Your advice is priceless
