Posted via email from Tropical Fish Supplies

I've a seventy litre (c. 15 gallons) tropical fish tank and I was wondering what the best starter fish would be. They need to be cheap and easy to look after.

I want a few fish in the tank and to feed them on flakes, not live food.  They need to get along and be brightly coloured and lively.  I'd like to have some different types of fish in my tank.

There are a couple of rules of thumb that you can use to decide.  The first is based upon the volume of water in your tank, and the second is based upon the tanks surface area.

First things first, you need to limit the amount of pet tropical fish to 100mm by length for every 18 litres of water in your fish tank (roughly 4 inches of fish per 4 gallons - 1" per gallon).  Of course you must take into account the fact that for a given length of fish, some species are going to be fatter and therefore produce more waste, need more oxygen etc, so a little common sense won't go amiss here.  Also, please note that the volume referred to is that of the water, not of the tank - you will have gravel, ornaments etc taking up volume - basic Archimedean stuff really!

Your second rule of thumb, is to consider the surface area of water.  This rule states, that for every 2600mm² you can have 100mm by length, dropping to 100mm of fish per 4300mm² for larger fish (or for you imperial bods out there, 1" per 12 sq. in. of surface area dropping to 1" per 20 sq. inch).  This rule takes into account the available area for oxygen exchange -  obviously enough, at the water's surface.

For regular, rectangular or circular tanks, your best bet is to use the volume rule, whereas for irregular tanks, use the surface area rule.  Also, you should consider the length of you fish as adults, not as you bring them home from the pet shop.

And finally... when you introduce your fish be wary to do so slowly, allowing the tank and its population of bacteria to acclimatise to the increasing bio load that additional fish will create.

unce asks: I got a fish tank filter from my aunt who bought the European model by accident and gave it to me.  Its a good filter and I want to use it at home but it's a euro-plug - I'm in the US.  What do I need to get, to be able to use it, bearing in mind that in the US we have a 110v supply and in Europe it's 220v?

Admin did some digging, and found out that:

You should really speak to a qualified electrician first and foremost.  It is possible to use European electrical products in the US, but it's not for the uneducated.

Air pump
Filter
Heater
Lighting
Powerhead(s)
Bottom material, e.g. gravel
Decoration

This article will cover the following:

fish tank pump; fish tank filter

Like us humans, your fish need oxygen.  Unlike us, they cannot breath it from the atmosphere, of course, they have gills with which to extract their oxygen from the water in which they live.  But this will need replacing, just as for us in an enclosed space, eventually the O2 will run out.  So what does the pump do?  Well, it circulates the water, causing turbulence at the surface thus allowing the absorption of oxygen from the atmosphere into the water.  Generally, you should not need to add oxygen to your tank by any other means, except when the ambient temperature is higher - but heck, is that likely in dear old blighty?

Filtration is essential for the health of your tank.  You need both mechanical filtration and biological filtration.  Don't panic, it's not at all complicated.  Just remember, the two type of filtration are not separate.  Biological filtration depends upon mechanical filtration, which sieves out particles from the water.  This really does assist the biological filtration process, and as a happy side effect will keep the water sparkling clear.  Biological filtration is essential in order to make sure that the waste products which your fish will produce are broken down to prevent them damaging the life support system.

Your local water supply will contain pollutants.  Now that's not to say that it is unsafe, oh no - you drink it, cook with it, wash in it etc, so it must be potable.  What I mean is that the very things that make the water safe for us to use, actually make it unsuitable (as it comes out of the tap) for you new friends to live in.  So how do you overcome this?  Well,in this life, very few things are insurmountable, and this issue is not one of them.

Water isn't just water though - it varies tremendously in quality.  It must be of a quailty suitable for the species of fish and invertebrates, and types of plant that you intend to have in your tank.  Understanding this, and how to measure and regulate it will help you to keep your aquatic environment in tip-top condition.  So, I guess that the best way to put it is, that you are making a commitment to your piscine friends that you will carry out such routine maintainance to their home so that they can live in comfort and without undue stress.

In addition to the ongoing processes of filtration and pumping you will need to carry out tasks such as changing the water and cleaning the tank sides and the gravel (by syphoning).  Your fish tank filters too will require cleaning from time to time.  You would do well to work up a schedule for these tasks so that you can make sure that they get done.

You should not attempt to change the water all at once.  It is recommended that you only change around a fifth of the volume of water, and that you do this once a week.  Changing all of the water would be harmful to the eco-system that you have set up in the fish tank.  As part of the biological filtration system, you will have established a population of beneficial bacteria - changing all the water at once will only serve to take you back to square one in this regard.  You tap water will contain chlorine and possibly levels of flourinethat are dangerous to fish.  When you run water from your tap you will be able to remove these chenicals simply by allowing it to stand for an hour or so.  However, you will still have other chemicals present in the water, in particular heavy metals, e.g. if your house is old, you will probably have at least some lead piping.  Good old water, the universal solvent will remove infinitesimally small amounts of lead from your plumbing.

Although not present in quantities likely to be dangerous to humans, your fish will tell a different story - they're much smaller than we are for a start, so the amount of toxin liable to cause them problems will be correspondingly smaller.  Therefore, you are advised to use a preparatory product such as Tetra Aquasafe in order to bind these heavy metals into non-toxic compounds.  But, as always, I urge you to check with your local supplier.

To summarise, there are things that will be present in your tank that you cannot see.  Obviously, that doesn't mean that they aren't here.  Leaving your fish tank to run for even a short length of time without attempting to manage them will result in quite a rapid degradation of the eco-system within it.  Your new friends won't appreciate it (when they float on their back, they're not relaxing!) and your investment will have been wasted.

For more in depth (sorry, pun unavoidable) analysis of some of the subjects covered here, please visit:

The Tropical Fish Expert

The Tropical Tank

So, first things first.  In order to choose from the myriad tropical fish tanks out there (it seems like there are as many tanks as fish), which should you choose?  Take a piece of paper and write down these questions:

Which fish do you want to keep?
How much space do you have available?
Do you want the tank to form a piece of furniture?
How much cash do you have to spend?
What shape of tropical fish tank would you prefer?

As with anything else in this life, one of my favourite cliches is true.  'You get what you pay for.'  And furthermore, you have to consider running costs as well as your initial purchase costs.  It may sound obvious, but:

The larger the tank, the larger the setup and running costs.
The more time you need to maintain your tank.
You will need to physically reach all parts of the tank.
Larger tanks will be harder to move and transport.

When you consider them full of water, they will weigh more.  As a rough guide, one litre of water will weigh a kilogramme.  Then when you consider the tank, stand and other items, every litre of tank volume probably accounts for 1.3-1.5kg of weight. Tanks are heavy, and need a very stable floor surface. With tanks over 250 litres it's well worth considering the strength of the floor.

However, the larger the tank you buy, the more stable its conditions will be, and the more fish you will be able to accommodate.

Notwithstanding the previous section, you have a choice of material for your tank.   There are two choices - glass or acrylic.  Acrylic is the lighter tropical fish tank material.  Therefore, it is easier to handle.  Furthermore, it is stronger and can have better optical qualities.  However, acrylic scratches more easily, is harder to repair, and in common sized tanks is more expensive.  Therefore, in common sized tanks 99% of people go for glass.

You will need something to sit the tank on.  For smaller tanks - less than 100 litres, a sturdy piece of furniture may be perfectly adequate, but it must be strong and level. Alternatively, you could use a stand or a cabinet.  Again, you get what you pay for.  A simple stand stand is just that - made from wood or metal, the tank sits on to of it.  You can buy them in common sizes or you could make your own.  A cabinet, as its name suggests, is more elaborate, and will often incorporate useful storage space.  Be careful not to allow your costs to run away with you.  Ultimately, you are buying a tropical fish tank, not a sideboard!

In order to even out any unevenness in the surface upon which you choose to locate your tank, you will need a layer of polystyrene or specialist material between the tank and its stand.  As with any purchase, it's best to shop around.  Consider second hand too but as always, remember, caveat emptor - buyer beware.

You will also need a cover for your tank.  This will keep your fish in (not as daft as it sounds!)  Furthermore, it will prevent any chemicals that may be present in the air from contaminating your tank.  Again, this is not as daft as it sounds, aerosols such as hair spray or deodorant ain't gonna do your fish a whole power of good.  Your cover will also provide housing for your lights, keep heat and water in and generally improve the look of the your tank.

Where will it live?  There are a number of points top consider in deciding where best to locate tropical fish tanks.  In no particular order, you should consider the following:

Sunlight.  Direct sunlight is not a good idea.  It could give rise to algae or over-heating, and it may reduce the tank's visibility.
Power outlets. Your tank will need a power supply for lighting, pumps etc.
Is the floor strong enough and level? You would do well to check with a spirit level.
The viewing position - can you see the blessed thing?
Take care to minimise vibration and pollution, be it noise or airborne.
Don't place the tank where it could be knocked and / or brushed past all the time.  You'll annoy the fish and increase the chance of the tank getting damaged.
Is the temperature stable temperature in the vicinity of the tank?  Fluctuating temperatures can cause problems and tanks in very cold areas will cost a fortune to heat.
A practical point - how close is the sink?  You don't want to be carrying water too far.

And finally, like a gardener with his plants, before he sticks 'em in the ground he will lay them out where he wants them to go.  You should take a few minutes with your empty tank in your preferred position for it - think things over before filling it, as it can be quite difficult to change!

And finally... at last we have a tank, filled with water and stood on a nice level, solid surface.  Fish may well live in it, for a while, but certain other equipment is required!  You're going to be maintaining a mini aquatic biosphere in your home, after all.

So what do you need?  Well, you need heating, filtration, lighting (more for viewing and to enable plants to photosynthesize than for the fish), and "other".  You can either select individual bolt on items from different manufacturers to fullfil your needs, or perhaps a better bet would be a systemised tank.  The second is probably easier, but may prove more expensive, and cut flexibility.  As ever, it's always worth shopping around for equipment, including online stores as these often have big selections at good prices.

Above all, use your local tropical fish supplies stockist.  They will know the ins and outs - and it's always better to speak face to face with a real person.  You can clarify points of confusion with them, and you may well find the best deals can be struck with them.  A bit of good old fashioned bartering never did anyone any harm!