Fishkeeping is a comparatively inexpensive hobby, but it is always nice to save a bit of money, and there are many ways to do this without risking the health or happiness of your fish. Imagination and innovation are your friends when it comes to finding creating, low-cost solutions to the demands of fishkeeping, but there's no substitute for experience, and many long-time aquarists will have tricks of their own that they have picked up over the years.

When I was doing my undergraduate degree in zoology, I learned all sorts of things from watching the aquarium technicians look after a wide variety of marine and freshwater organisms maintained in the research centre. Octopuses, for example, like to climb out of their tanks. For whatever reason they didn't like the texture of the nylon wadding normally used as a filter medium, so by draping sheets of this stuff over the edges of the octopus tanks, these ambulatory escape artists could be kept safely in their quarters. Another useful tip was to feed fish strips of squid. While aquarists rarely think about squid as fish food, most larger fish will greedily accept it, and since squid is so cheap, it makes a very cost-effective staple for things like predatory cichlids, gar, catfish, and so on.

Lighting 

A friend of mine likes to say that a poor man can only afford the very best. In other words, if you want something to last and not have to waste time and money on maintenance and repairs, then you need to get the best, not the cheapest. This maxim holds very well for many of the purchases aquarists make, such as the aquarium itself as well as pieces of electrical equipment such as canister filters and heaters. Not only do they need to work twenty-four hours a day, seven days a week, but we expect them to last for many years. 

On the other hand, there are some good ways to economise. Take the lights, for example. Most aquarists buy the tubes offered for sale in aquarium stores, and there's nothing wrong in that, but you don't have to use those if you don't want to. However, while you can use tubes not designed for aquaria without compromising safety, the same cannot be said for the cables and switches that you need to connect the lights to the mains electricity. Without fail, always use lighting equipment designed for use in aquaria, as these are designed to work safely in the warm, moist environment directly above an aquarium. If you have the choice, opt for electronic ballast systems. The older, magnetic ballast systems (the ones with screw-out capacitors and big bulky switch boxes) waste a lot of electricity as heat, making them far less cost effective over the long term. 

Off-the-shelf fluorescent tubes from your local DIY centre can easily save you several pounds per tube. Most aquaria in the UK use standard 1-inch diameter tubes with two-pin caps, and these are widely sold for use for office and domestic lighting as well. The factors to consider are wattage and something called 'colour temperature', best thought of as the colour of the light produced by the tube. A tube with a low colour temperature will have a red or purple hue, while a tube with a higher colour temperature will appear more blue or white. 

Plants absorb and use both red and blue light for photosynthesis, but hardly any of the green in between the two extremes. That is, of course, why plants are green: the green light bounces off the plants and into our eyes. Of the two, red light tends to stimulate better plant growth than blue, and so the lights used to grow plants in greenhouses have a reddish hue. Such tubes include the popular GroLux variety sometimes used in planted aquaria. However, red light doesn't penetrate water very far, and in tanks more than 30 cm  (12 inches) deep lamps producing predominantly blue light are much more effective. 

Colour temperature and wattage don't matter much if all you're keeping are fish. For these, simply choose a lamp that shows off the colours best. Tubes with a relatively low colour temperature, around 3000Ë° K to 4000Ë° K, will give the aquarium a pinkish tint that tends to set off the colours of red, orange, and yellow coloured fish especially well. An aquarium containing tetras, dwarf cichlids, or livebearers would be complemented nicely by one or two low colour temperature tubes. Fishes preferring darker conditions will appreciate these tubes as well, and adding a bit of blackwater extract to the water will beautifully re-create the murky, swampy habitat favoured by catfish, Mormyrids, spiny eels, and discus. Higher temperature tubes, on the other hand, give the aquarium a much more bluish-white cast, and this suits silvery fish especially well. Barbs, silver dollars, angelfish, monos, and scats would be fishes that would look good in a tank illuminated with such a tube. 

For tanks with plants, both wattage and colour temperature are critical. Tubes in the range of 5000Ë° K to 8000Ë° K will work well here as far as colour temperature goes, and most aquarium plants do best in tanks where there is at least 0.5 Watt per litre (about 2 Watt per gallon). The higher the colour temperature, the better the tube for lighting a deep tank, but the price to be paid is a bluish hue to the tank that some find unattractive. Adding a reflector to the back of a tube is a good way to optimise its performance, and is a low-cost way to get the most bangs for your buck. Something often overlooked is the need for regular cleaning: especially in tank with hard or salty water, both tubes and reflector can get covered in mineral deposits that significantly decrease their effectiveness.

Butts and buckets 

Every aquarist should have a bucket with a lid. While any bucket can be used to carry water, a bucket with a lid can also be used as a safe place to store or transport fish. Eventually, every aquarist will need to take apart an aquarium to redecorate or give it a thorough clean, and that will involve putting the fish somewhere else in the meanwhile. A decent sized bucket will do the job, but so many fish like to jump out of buckets that a bucket with a lid is much more useful. Moreover, while household buckets tend to be relatively small, containing perhaps two or three gallons, as a place to keep fishes, an even bigger container is much more useful. This is obviously the case when it comes to handling big catfish and cichlids, but also with any species intolerant of low oxygen concentrations or high nitrite and ammonium levels. For those sorts of fish, the bigger the bucket, the cleaner the water will remain, and therefore the longer the fish can be kept in the bucket safely. 

My favourite buckets are the 5-gallon ones made from white plastic. Because they are white, it is easy to observe any fish placed inside them. This is useful when you need to count the fish or check that they are still healthy. The lid stops my Hatchetfish and halfbeaks from launching themselves to a premature death on the living room carpet. These indispensable pieces of equipment are hardly ever offered for sale in aquarium shops though. Instead, you'll need to visit a DIY store or builder's merchants, where they will cost you around a fiver apiece. 

I really don't know how I lived without a rainwater butt. These are put underneath a gutter, turning your roof into a rainwater capturing system. A 100-litre water butt costs about $20 and will provide you with a regular supply of soft, nitrate free water. If you've ever fancied breeding tetras, killifish, Amazonian cichlids, or any other fish that need soft, acid water, then collecting rainwater is an almost zero-cost way to go. One potential hazard is ambient air pollution contaminating the water and poisoning your fish, but the risk of serious problems is very small unless you live close to a dirty factory or busy road. A net placed at the spout of the water butt will catch leaves and other bits of detritus that have been washed into the water as it flowed down the roof and gutter.

Aquarium planting and decor

After the water, the next most important thing inside an aquarium is the substrate. Most aquarists simply use plain, washed gravel because that's what's on sale at their local tropical fish store. Aquarium gravel is a fine choice, but there are alternatives. One of my favourites is silica sand, sometimes known as silver sand. A thin layer of this (no more than 2.5 cm or an inch) is a safe alternative to gravel that works especially well with digging and burrowing fish. An aquarist keeping catfish, Geophagine cichlids, gobies, freshwater soles, and spiny eels will find a sandy substrate allows these fish to behave in a much more natural way. Until you've seen a Corydoras with its head buried in the substrate with sand spewing out of its gills, you just haven't lived! Silver sand can be obtained from garden centres where it is sold primarily for use with potted plants and as a lawn improver. A 25 kg package contains more than enough sand to create a substrate for a tank a meter (3 feet) or so in length, and costs about $3. 

Ornamental cobbles and pebbles are widely sold for producing decorative areas around ponds and patios. Provided these are lime-free, these can be an excellent source of materials for decorating an aquarium. Larger fish look good set against larger stones, and in a big tank, creative use of stones of different sizes can be very dramatic. An aquarist re-creating a mountain stream, for example, might cover the base of the tank with a thin layer of sand or fine gravel, and then scatter some larger pebbles on top of that. A couple of large, water-worn boulders and the odd pieces of driftwood would perfect the illusion. Re-creating an African lake, on the other hand, would demand the use of many large pieces of stone to produce a rocky area around which the fish will naturally congregate. Big, angular pieces of granite can look very effective for this, and far more authentic than the tufa and lava rocks more frequently used by aquarists. The key thing is to stick with just one kind of stone: mixing different types tends to shatter the illusion that the aquarium is a snapshot of a particular natural habitat. 

Bamboo and coal are two often overlooked materials that can work well in the aquarium. Coal (specifically: anthracite coal) needs to be washed well before use, but once it's clean, it makes a safe and interesting decorative material for certain types of tank. Used alongside a dark substrate, coal lends the tank a very distinctive quality that works well against fish that have a luminous quality, such as neons, cardinals, and Glowlight tetras. Bamboo is another material that can work outstandingly well in the right tank. Ideally, arrange the lengths of bamboo so that the tops are above the waterline, so that when the aquarium is viewed, the bamboo seems to be growing out of the aquarium. This gives a tank a very oriental quality that complements Asian fish such as barbs and gouramis exceptionally well. Note that bamboo doesn't last for every in an aquarium, and will need to be replaced after a year or two, but given that a bundle of bamboo canes will only cost a pound or two, this is no great penalty. 

PVC pipes and clay flowerpots can be very useful for the aquarist keeping or breeding certain types of fish. Many burrowing or nocturnal fish like to use burrows during the day, and in a gravel aquarium this can be difficult to accommodate. Short lengths of PVC pipe, easily purchased at a plumbing store or DIY centre, can make a fine substitute. The large bore stuff, such as guttering and drain piping, is ideal for catfish, while narrower pipes will be readily used by things like spiny eels and violet gobies. Most fish want a length a bit bigger than they are, and it's important to make sure that enough is used to keep all the fish happy. Ropefish, Erpetoichthys calabaricus, for example, are sociable and enjoy quarters that allow the whole pack to hang out in, whereas gobies and Plecs tend to be much more territorial and won't want to share. Flowerpots are enjoyed by fish that like shelter rather than an actual burrow. Cichlids, Mormyrids, and pufferfish will appreciate a flowerpot placed on its side, and in many cases will use these as a place to breed, as well. While flowerpots and plastic pipes may not have the same aesthetic appeal as, say, skull-shaped aquarium ornament, they are functional, non-toxic, easy to clean, and very inexpensive.

Garden centres can be a good place to pick up aquarium plants, too. To be sure, most pond plants aren't going to do well in aquaria, but some will. Among the species most regularly seen in garden centres are hornwort, hairgrass, and Canadian pondweed. Hornwort, Ceratophyllum demersum, is a floating plant that really earns its keep in the livebearer aquarium. It is a first-class have for newly born fry, which snuggle up within the plant safely hidden from the other fish in the tank. Hornwort does well in hard water and is tolerant of relatively low lighting levels. It is also an excellent algae-suppressor because it releases chemicals that inhibit the growth of algae. Hairgrass, Eleocharis acicularis, is one of the plants du jour when it comes to aquascaping, thanks to its attractive shape and modest size. Its leaves get to about 10-15 cm in height, and form a nice foreground a bit like a grass lawn. This plant is sold as a marginal and an aquatic for ponds, normally in square tubs. Each of these tubs contains hundreds of individual plants that are best used teased apart and planted in a rich substrate about 2 cm (an inch) apart. Finally, Canadian pondweed, Elodea canadensis, is a hardy plant than needs hard water and bright light to do well, particularly in tropical aquaria. Beyond that, it's easy to keep, and makes a good background plant for large tanks with robust species. Buying these species as pond plants is often much cheaper than buying them as aquarium ones. Hornwort and pondweed typically go for around $1 a bunch, while a good-sized pot of hairgrass will cost less than a fiver.

Food 

One of the ongoing expenses in fishkeeping is feeding our charges, but again, there is plenty of scope for economy. Flake food is probably the ideal as far as a staple diet goes, since it is carefully balanced to include all the necessary nutrients and vitamins, just as with humans, your fish will enjoy a varied diet. The frozen food cabinets at your local grocery store are a great place to begin. Mussels and prawns make excellent foods for many predatory fish. Pufferfish, Plecs, and large cichlids are especially fond of mussels, while smaller fish such as tetras, gobies, glassfish, and barbs will readily take small pieces of prawn. Predatory fish relish strips of squid and white fish, but since frozen food is difficult to cut, it is a good idea to buy these things fresh and then slice them up before freezing them. 

A treat enjoyed by many small fish is a meal of prawn eggs, which during the springtime can be found on unshelled North Atlantic prawns. You can buy these at the seafood counter, and the prawns are easily scooped off and frozen for later use. Fishes that are otherwise considered fussy eaters, such as glassfish and gobies, particularly enjoy these eggs. 

 Anytime you're preparing fresh fruit and vegetables, it's definitely worth thinking about whether your fish would enjoy some too. Again, there are good pellets and wafers that are can provide the perfect for herbivorous fish such as Plecs, but giving your catfish something different every once in a while will keep it happy and healthy. Celery tops, lettuce leaves, melon rind, carrot, potato, courgette, and cucumber will all be nibbled on happily by Plecs, and to a certain extent by omnivorous cichlids, mollies, scats, and many other fish. Because green foods contain little protein, they won't release ammonium and nitrite, even if they do fall apart and make a mess, so don't be shy about leaving them in the tank for a day or two to soften up. Most herbivorous fish like their greens a little on the soggy side!