eRodent > Tropical Aquarium > Before you buy a tropical aquarium.


Before you buy a tropical aquarium.

Juwel Rio 240
Looks pretty but it's been a world of hassle.

I read somewhere that 2/3 of people who buy tropical aquariums give up within a year. I don't know if this is true, but eBay is certainly full of second hand kit going very cheap. A depressing little anecdote from a pet store yesterday. Small girl saying to man "my dad bought me some of these neon tetras from (name of local fish shop) and they all died - one was dead in 20 minutes". Man "must be a rubbish shop - lets get you some from here". Just a little bit of knowledge could have saved those tetras and thousands of others each year.

So in the spirit of the popular before you buy a chinchilla page I thought that I'd set up a similar page for tropical fish tanks as my new one has proved many, many more times the trouble of the chinchillas! This page is currently a work in progress and will be updated as I go along. Please bear in mind that I wrote the articles on rodents with the benefit of years of experience, this page is simply what I have learnt whilst setting up a planted aquarium as a newbie and I am far from an expert. I strongly recommend that you join a good forum and find out more.

  • Do your research, and then do some more.


  • If you're reading this article, then the chances are that you are the sort of person who will successfully set up an aquarium, as you already know the value of doing your research. But do as much as you possibly can, including lurking on a good forum such as the Practical Fish Keeping Magazine one for several weeks. There's nothing like reading about everyone else's mistakes for preventing you making them yourself. I find this forum helpful and friendly and usually get good advice there. It's downside there is that it is against the rules to criticise companies for fear of libel action against the magazine/upsetting advertisers (which I kinda get but it means you won't hear about problem shops or suppliers). There are of course other good forums - this is just the one I like best. Always be aware that anyone can give advice, and it won't always be right - there are some very opinionated people out there on forums who think their way is the best simply because they've always done it like that.

  • It's vastly expensive.


  • The cost of the fish is minimal, but even the cost of the tank will pale into insignificance against the cumulative cost of everything else you will need. Even small things seem to add up. And that's before you decide if you want a second tank to quarantine new fish in. It's also worth mentioning that a larger tank will need more of everything - it's not just the extra cost of the tank. But once done larger tanks are supposedly easier to keep stable. It is certainly not a cheap hobby. Planted aquariums can be particularly expensive because of the cost of the plants, the CO2 systems, specialist substrate and fertilisers - see the Planting the Aquarium page for more details. It's scarily easy to break something expensive. I accidentally dipped the end of the lighting unit into the water and it cost me sixty quid for new tubes and all the time and hassle of getting them.

    This is not an exhaustive list but will start to help you cost it up:

  • Tank, filter, heater, lighting and reflectors, thermometer, extension lead, timers
  • Substrate, decor, background
  • Water Conditioner, filter start product, ammonia source for cycling (see below)
  • Test Kits: Ammonia, Nitrite, Nitrate, Narrow Range pH, Phosphate, KH/GH
  • Fish food
  • Net, algae cleaner, gravel cleaner/siphon, buckets, large vat to heat water change water, plastic sheets and old rugs/towels to protect the furnishings
  • Spares for filter e.g. pads, impeller, possible spare heater (useful for heating water change water)
  • For a planted tank: Plants (surprisingly expensive), CO2 System, Drop Checker, Plant Fertiliser, plant trimmer/planting tools
  • Consider complete quarantine setup to prevent introducing diseases to your tank
  • Oh and fish - I currently have 6 worth of fish in a setup that cost over 1000


  • Although the largest tank you can afford is often recommended, there's something to be said for getting a small setup - say about 60l first with half a dozen tough fish, and if you enjoy the hobby you can make this your quarantine setup when you buy a larger tank.

  • Thoughts on eBay.


  • You can get yourself a real bargain on eBay or many other websites such as gumtree or aquatics classified. One of those 2/3 of people giving up will probably throw all their bits and pieces in with the deal, but take care or you may also get a headache as spare parts can be scarily expensive. Check with the seller what is included, sometimes it's just the tank or there won't be a filter, lighting or heater which can cost a big percentage of the price of a new tank.For example a new Juwel Rio 240 is 350, but the lighting unit with tubes could cost 150+ on its own.

    Large setups can be amazingly good value if you know what you are looking for an have access to a big estate or small van to transport, but looking at what smaller ones go for personally I'd buy one new and cut out the pain.

    Setups with fish included are usually only for the experienced fishkeeper. The fish, and particularly the mature filter, need to be treated with great care. They are often heavily overstocked, so you are looking at finding new homes for at least some of the inhabitants - and homes for 16" plecos aren't easy to find! However, that said, it can be a very rewarding thing to do - just read up carefully on moving fish tanks - there are lots of threads on forums about this subject.

  • It's vastly time consuming and really quite hard work.


  • It took me half a day to set my 240l tank up initially, I then got a problem with my gravel and had to empty everything out and do the whole lot again, finally I had to do a 75% water change at the end of my cycle (see below). That's a lot of water to be lugging around in 10l buckets and putting carefully into the tank using a jug! Then I will continue to have to do weekly water changes of about 30-50l. These are of course less with a smaller tank. See the Setting up the Aquarium page for details of setting up.

    When you first set up your tank expect to be spending quite a bit of time dripping chemicals in test tubes as you cycle it and get it ready for fish. These will be ongoing, if slightly less often, but you will also need to do regular water changes, maintain your filter, feed and check the fish, clean the glass and trim any plants etc.

    It's also worth thinking at this point about when you go on holiday - have you got someone you can rely on to check that everything is running smoothly and feed the fish whilst you are away?

  • You wanted fish in your tank?.


  • It took me two whole months to get any fish in my tank. Admittedly this was a little extreme as I had a few unusual problems and caught a nasty lurg early on, but it isn't unusual to have to wait a month. This is because you need to ensure that the filter has enough good bacteria to be able to handle the fish wastes before putting them in. Some fish shops still advise the practice of using a few hardy fish to 'cycle' the filter, but this is very unkind to the fish and will shorten their lives at the very least - it is far better to use an ammonia source such as Biomature and do fishless cycling. See the Maturing the Aquarium page for more details.

    Even once you have cycled you need to add fish slowly to the tank and continue to test the water regularly to ensure that their waste products don't build up. Fish can also sadly carry diseases and only a few shops quarantine for any length of time. This means you might want to consider a quarantine setup as well - more time and expense. I introduced my first fish with no quarantine thinking that there was no-one to pass illness to - then discovered that they had a problem that required a medication that killed snails. This resulted in the major job of trying to pick out every single pest snail from the tank so that they didn't die and contaminate the water as they rotted.

    Fish shops nearly always overstock the display tanks that they have giving you a false impression of how many fish you can actually keep in a tank. So you will have to make some hard decisions about what fish you really want. Often you find that the ones you had in mind when you bought the tank are either too sensitive, or aggressive or aren't suitable for your water.

  • You will be told absolute rubbish.


  • Sadly there is a lot of rubbish advice out there and much of it comes from staff in fish shops - many of whom should know better. The worst sins seem to be advocating using fish to cycle the filter, and selling unsuitable fish. Selling a common pleco that will reach 16" to someone with a 2 foot tank or a sensitive soft water fish to a beginner in a hard water area aren't really excusable. Do your own research, don't rely on the guy in the fish shop to guide you. Many of them are very good and very knowledgeable, but it's good to have the basic knowledge to recognise good advice when it is given.

  • You will be sold unsuitable stuff.


  • It's absolutely essential that you check that everything you buy is fit for purpose before buying and using it. This ranges from the fairly harmless battery powered gravel cleaners that just aren't powerful enough, through annoying substrates that raise the hardness of the water because they have limestone in them, to the downright dangerous such as water treatments with copper that will kill all your snails and shrimps.

    You have to accept that there will be mistakes along the way but at least we have the Internet nowadays and you can search for other people's opinions on everything that you buy. And check everything when you get it. My tank had somehow been fitted with the wrong power head and if I'd known exactly what the filter should have contained when I bought it I could have spotted this when it was delivered rather than a month later.

    There are a large amount of water treatments available that have the potential to cause more problems than they solve. Some are absolutely essential such as water treatments to remove chlorine from tap water and others may be helpful, but the jury is out, such as the products that it is claimed kick start your filter. Others are good as long as they are used correctly, for example Biomature will cycle your filter without fish but should never be added with fish in the tank. But there are those such as chemicals that kill algae or alter pH that you have to be very careful with or you could end up giving yourself a tank full of dead, rotting, algae or an unstable pH which could kill fish. My personal opinion is always look for solution that doesn't come out of a bottle first. For example such as buying plants that out compete algae or choosing fish that suit your pH.

    The advice to research is doubly true for fish; there are unsuitable fish for sale everywhere. Buy the wrong ones and you could end up with dead fish, a fish that grows to two foot long and trashes your tank, or one large and well fed fish in your tank when all the others have mysteriously disappeared overnight. You have been warned!

  • Quarantine, quarantine, quarantine.


  • Now I know a bit more about it I can't believe how often I've seen fish with obvious signs of illnesses such as white spot, fungus or parasites in fish shops. Even if there are no visible signs it is also possible to buy fish with infections that will spread to all of the fish in your tank. It's not cheap to buy a second small setup for quarantine but really worth it to avoid heartache. A good shop will quarantine all stock for a couple of weeks at least but it's actually quite difficult to find one that actually does. The quarantine setup will, of course, also need carefully cycling.

  • When fish get sick it's a real problem.


  • Vets don't generally deal with tropical fish and generally you have to diagnose the problem yourself and buy and over the counter remedy. Many of these are ineffective at best, totally useless at worst. Knowledge on fish illnesses is in pretty short supply and I've been given some truly woeful advice both in fish shops and on forums. So if you get a sick fish you will need to do quite a lot of research and reading. Many fish diseases also tend to be symptoms of poor water quality so that regular maintenance is essential.

  • Learn to love your water.


  • Yes you can fill your tank with reverse osmosis water or play with chemicals which change your pH, but these things are hard work and have potential for disaster if you get it wrong. Every time you do a water change you have to ensure that the water that you are adding is exactly the same as the changed water in the tank or you risk shocking your fish. If you've just started out it's a lot better to just accept the tap water you have and choose fish that will enjoy it. Yes I had to accept that neon tetras weren't going to like my rather hard, alkaline water but it did give me the opportunity to find out about all sorts of much more hardy and even more attractive tetras that I could keep. I would really advise getting tough fish that suit your water conditions first and when you have the experience move onto the more unusual types.

    While we are talking about water it's probably worth mentioning that your water change water will need to be heated up, particularly in winter. If you have a nice modern combi boiler or tank you can probably get away with using hot tap water, but otherwise you will need to rig up some sort of system to heat it up. I have a 30l, food grade barrel and a spare heater to prepare it in advance. See the Maintaining the Aquarium.
    page for more details.

  • Is it really ethical?.


  • This is an essay in it's own right and you will need to make your own mind up about this one. But many, many fish die each year in unsuitable tank conditions when they have been miss sold. And this is after many have died making the journey from where they have been caught in the wild in South America or bred in huge vats in the far east. There is probably some merit in the argument that if done sustainably, catching tropical fish for export provides employment for local people as an alternative to exploiting the forests. But it can also have devastating effects on local populations of fish, particularly when a new fish becomes trendy and in demand.

    Many fish shops are also a disgrace, with dirty tanks, badly labelled unsuitable fish and poor advice from the staff. Strangely this can also apply to shops that have been well recommended online and in magazines. So my advice is to go and visit every shop in you area, and make a decision for yourself about whether you are happy with the conditions that the fish are kept in and the advice you are given. Look for spotlessly clean tanks, separate quarantine facilities and fish labelled with their Latin name, their adult size and what sort of setup they are suitable for. Try, if possible, to avoid buying anything in shops that aren't up to scratch as they make most of their money on dry goods not the fish. That said it can be very difficult when you need something in a hurry, or cannot find it elsewhere an I'm certainly guilty of buying things in shops I would never have fish from because they have it in stock. One of the problems for good fish shops these days is that people can get things much cheaper online and I will always happily pay a little bit more to get something from my good local shops. But sometimes it's just a case of not being able to get things locally (plants are a particular problem around here) or large items costing 50-100% more.

    Do you like this page? Is it useful? Please email me at paula@eRodent.co.uk and let me know. Put something about aquariums in the title so I can pick it out if my spam filter gets it.

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