How to set up your Christmas tank


With the festivities just a couple of weeks away, let’s investigate some of the pitfalls of Christmas and aquaria, for both newcomers and experienced aquarists alike.

Absolute beginners!

There’s a pretty strong chance that this is your first time reading a PFK article — this may even be a part of your Christmas package along with an aquarium and a gift voucher that you’ll be itching to spend on fish on Boxing Day. So, let’s see if we can stop you racing headfirst into the jaws of ruin, as so many newcomer aquarists are prone to doing…

Your first tank — should you upgrade it?

Here’s a crazy thing you’d not expect. It’s a whole lot easier to run a large tank than it is a smaller one, and I say that as someone who has kept goldfish bowls (near impossible) as well as worked with 250,000+ litre systems (easiest job of my life). For reasons of stability, a large body of water is much easier to keep fish in than a small one.

Temperatures can shift up and down quickly in a small volume of water, while even a tiny amount of pollution that would be toxic in a tank of a few litres can be diluted and rendered harmless in a pond.

As a starter, I would advise looking at a tank of around 60-litres capacity or more. This will provide a happy medium of enough stability to account for some newcomer errors (believe me, there will be a few) without being so large that you feel intimidated by its maintenance.

If you have a tank of around 20 litres or less, your choices as a first-time aquarist will be limited. Don’t expect to keep fish in it, because something that small and unstable is at best suited to a few shrimps and some plants. Go bigger for success — nobody ever regretted starting with a larger tank.

Siting your tank

Here’s hoping that the store gave you some advice on where not to position your aquarium. If not, then here’s a list of places to avoid around the home.

Close to doors — If you’re in the swinging arc of the door, you could smash your aquarium outright, and even if you’re not, the tank will be upset by draughts, the shock of people walking through the door (fish are mighty nervous) and the sound of doors slamming shut.

In a busy hallway — Or anywhere with a lot of human traffic. Hallways are where tanks are most likely to be collided with, which not only risks breakage, but also spooks the fish every time someone passes by.

In front of a window — Not only will you expose your fish to the risks of sunburn and cold draughts, there’s even the risk that some novelty aquarium shapes (bowls) could act like a magnifying glass in direct sunlight, leading to a fire risk.

Near stereo or TV speakers — Fish have exceptional hearing (they have well developed inner ears, often using the swim bladder in their bodies as a kind of drum to amplify sounds) and the vibrations from loud music or home cinema will stress them, leading to weakened immune systems and disease.

Directly over plug sockets — Water splashes out of tanks, and the last thing you want is for it to land directly on to any electrical sockets. Ensure sockets are nearby (because you’ll need a few of them) but not close enough to get splashed.

In a kitchen — You get a lot of fumes and airborne chemicals in a kitchen, and water is extremely efficient at absorbing them all.

In front of a radiator — Guaranteed to cause temperature fluctuations and potential overheats that will stress and harm fish.

Setting it all up and decorating

This stage is pretty easy, but there are a few things to note that could cause a problem.

Soaps — Don’t use them to clean your tank. Don’t use furniture polish or window cleaner on the tank (unless it specifically states that it’s aquarium safe), as it could all be toxic to fish. Clean with water, kitchen towel and soft cloths without fragrance.

Wood — Almost any wood needs to be soaked before going in a tank, because it contains humic and tannic acid that will stain the water a dark reddish hue and lower the pH significantly. Soaking time varies, but never put wood straight in the aquarium. Also, don’t collect your own woods until you’re a lot more experienced — rely on aquarium suppliers. If your water does turn dark brown within days of adding it, pull it out and carry out a series of 25% water changes for a few days until it clears.

Stones — If a rock is powdery and chalky, the chances are that it can make your water harder and more alkaline. Slate, granite and cobbles are good choices for the starter, but don’t think that any old rock will be safe. It often won’t.

Substrate — It’s largely a matter of taste, but substrate choice will affect the fish you can eventually keep. Many catfish, for example, fare badly on gravel and need a fi ne aquarium sand instead. Some coloured gravels may be made of dolomite, which can make the water harder and more alkaline. As a newcomer, avoid ‘planting soil’ substrates, as these are targeted at aquarists who want to focus on planted set ups. Aquarium silver sand is inert, cheap and easy to work with for a starter.

Cycling — the most important thing you probably don’t know about

This is really important right here. If you set your tank up, race out, buy all of your fish in a few days and hope for the best, your tank will fail, the fish will get diseases and die, and you’ll have to start from scratch. This is without doubt still the single biggest reason that aquarium fish die in the hobby.

Your filter needs to be nurtured — An established aquarium filter is a colony of living, breathing organisms, mainly bacteria. The problem is that it needs to be colonised, and that takes time.

When you set up a tank, you have next to none of these filter organisms alive, and so you need to provide a food source for them to culture on, using artificial fish waste (later, when the filter is fully established, these organisms will get all the nutrition they need from the fish themselves). Dr Tim’s Ammonium Chloride is a great choice, and you can pick it up from select aquatic stores as well as online — get some Dr Tim’s One and Only at the same time, to help kickstart the growth of your filter.

Alternatively, you can purchase some household ammonia, and use one of the online calculators (if you put ‘aquarium cycling calculator’ into a search engine, you’ll get many results) to advise you how much of it to add to your tank and when. Believe me when I say that using an online calculator is a lot easier than trying to use the long-winded formula that I could offer instead.

You’ll also need a few test kits, so that you can test for the pollutants the filter should (eventually) be controlling. Ideally, get an ammonia, nitrite (those are the big two), nitrate and pH testing kit to help you through what we call the ‘fishless cycling’ period. Essentially, what happens during a cycle is that you add ammonia to the tank and the levels will rise. Eventually, nitrite levels will rise and ammonia levels will fall, and sometime after that, nitrate levels will rise as nitrite levels fall. It’s only once your test kits show that there’s no more ammonia and no more nitrite that it’s safe to add your first fish, because that then means that your ‘living filter’ is alive and well.

There’s a whole lot more to this process than I’ve touched on here, but these are the basics. If you do want to learn more (and it is kind of essential to successful fishkeeping that you do) then you might want to pick up a copy of the Practical Fishkeeping Masterclass, which explains it in much more depth.

Stocking and selecting fish

Building up a fish collection is slow. It’s going to take several weeks of adding fish gradually until you can have all the fish you want in your tank. In a volume of 60 litres or so, start with around six fi sh, and only after you’ve cycled the tank as above. The aim is to increase the number of fish slowly, allowing the ‘living filter’ time to grow and adapt to the newcomers with each addition. Assuming that your water tests consistently show no ammonia and no nitrite present in the water, you can expect to add around six more small fish each week (or a pair of larger ones, for example) until the tank is fully stocked.

The annoying bit is that you’ll not be able to add all and any fish and expect them to live harmoniously. Some mismatches are obvious — fish with big mouths have a tendency to eat small fish, for example, and you might be able to spot a poor decision in advance. But there’s also the water chemistry stuff that isn’t immediately obvious.

Just as there are differences between, say, freshwater fish and fish from the sea, there are similar differences between freshwater regions and the fish that live in them. For example, a large number of fish from the Amazon rainforest live in water that has a low mineral content and is steeped in acids. Meanwhile, fish such as those from the Great Lakes of Africa live in water that is absolutely packed with minerals and is comparatively alkaline. The fish from each of these regions have evolved certain physiological functions to fi t them best to their environments, and putting them in the wrong type of water will kill them.

Before making a stocking plan of the fish you want to keep, find out the water hardness and pH of your own aquarium. If you’re going to avoid problems in stocking, you’ll need to choose fish that are suitable for your existing water parameters. Your retailer will be able to help you with this (or at least they will as long as they know what your pH and hardness are).

Do not overfeed!

It is surprisingly hard (but not impossible) to underfeed fish, but mindbogglingly easy to overfeed them — especially the types of fish you’ll be cutting your teeth on as a beginner aquarist. The tendency is to want to interact with your fish as much as possible, and seeing as feeding is the main way that we do that, the urge is to feed every time you’re nearby. But you need to be firm; overfeed and you’ll likely end up killing them.

Fish need about 1% of their own bodyweight in food per day for maintenance reasons — energy, muscle building, tissue repair and such — and anything over this is going to be excreted as an excess of harmful ammonia. That puts an extra burden on your filter, and the result is that fish start to become exposed to harmful levels of pollution, leading to illness.

For the first few weeks at least, dial back the amount you’re offering. Maybe aim for just one feed a day for the first fortnight, and limit it to how much the fish will eat in around two minutes. At the end of a feed, use a fish net to remove any uneaten food floating on the surface, or gathered on the substrate (remember to check behind stones and under decoration).

Monitor the shape and ‘plumpness’ of the fish as you do this — in the highly unlikely event that the fish start to look gaunt and pinched, you can increase it to two feeds a day. But I’ll wager they won’t.

Established keepers

Even if you’ve been around the fishkeeping block a few times, I’ve seen a few situations that crop up year on year. Here are a few that are more in the realms of the experienced aquarist…

Festive pitfalls

Christmas clean up — We’ve got the family coming around for a slap-up Turkey dinner and Quality Street binge, and many of us take the opportunity to spruce our tanks up for our guests. Once you get started, don’t get carried away; a thorough clean can be more than your aquarium’s in-built ecosystem can handle. Keep water changes at less than 35% of the water, and don’t be tempted to go ballistic on the filter cleaning. If the tank’s looking a bit shabby, do a couple of small cleans in the week running up to guests arriving, and don’t be tempted to try and do too much in one hit. Your biofiltering will love you for it.

Pine needles over tank — A new entry for 2021 and one that comes with the advent of so many open-topped tanks. I had a conversation early last year with a retailer who saw a customer accidentally poison their fish with pine needles from their Christmas tree (the tree was wedged right next to the open topped aquarium and a lot of needles had fallen in). Whether there was something toxic in the leaves, or whether the tree had been contaminated with insecticides isn’t known, but it’s a hazard to be aware of.

Check those nitrates and phosphates — Lost a few tetra and barbs over the last twelve months? Tank looking a bit sparse now? Before you race out and fill back up on a few new shoals, test your water. If you’ve even been slightly lax with your waterchange and cleaning routines, there’s a chance that nitrate levels will be sky high while pH and hardness levels are on the decline. That might not be enough to upset the fish already in your tank, but if your local shop is better maintained with harder, more alkaline water and less nutrients floating about in it, the shock from adding new fish to your mucky system could easily be enough to weaken immune systems and cause disease outbreaks.

Other peoples’ kids — I mean, this one should be obvious, but keep an eye on them, especially if they’ve never been introduced to fish tanks before. If they haven’t, there’s a high chance they’ll tap on the glass.

Yule cigar — I’m deadly serious on this one, and I saw it happen too often in my retail years. If you enjoy a Christmas cigar, make sure you don’t have it anywhere near your tank. The nicotine and myriad other chemicals released in the burning process can wipe out a marine reef in record time, and have blighted more than a few prized freshwater layouts. The same applies to vaping.

New plant overhaul — If your tank needs a lot of new greenery, make sure you’re buying from a source you know and trust. Some freshly imported plants from the far east are treated with a variety of pesticides which won’t harm fish (as far as we know) but will demolish any shrimp populations you might have.

Champagne corks — We all know (or we should know) that once we’ve taken the wire off of the top of a Champagne bottle, we should never point it at another person. The same sentiment extends to aquaria!

Perfect gift for beginners!

The Aquarium Masterclass is the perfect guide for beginners covering all the basics in details that you will need to keep your new tank thriving. Why not treat yourself or someone else this Christmas?

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