Water: the essential element for fish

The texture of good quality water is subtle

Water: the essential element for fish

The texture of good quality water is subtle
The texture of good quality water is subtle

On a very basic level water is 99.98% H2O in a liquid that your fish swim, eat, breathe and excrete into. What about the other .02%? Is it important? Of course it is. It is these minute quantities of dissolved gases and dissolved solids that makes all the difference in whether the water is hospitable or poisonous to the fish. It is this 0.02% of dissolved substances that make sea water, river water and lake water different from each other. Note that seawater has a much higher level of dissolved salts of around 3.5%. It only takes minute quantities of the common gases such as ammonia, carbon dioxide or insufficient oxygen to poison or drown fish. Likewise it only takes a small amount of pollution or the wrong type of chemical to be dissolved in the water to poison and kill fish. But when conditions are just right or within reason then your fish will thrive without much care from you.

Creating a generic biotope for your fish to live in

The most common elements of an aquarium biotope
The most common elements of a biotope

As a fish keeper is is your responsibility to recreate a reasonable biotope for your fish that is as close as possible to the fish’s natural environment as you can.

Water has dissolved gases such as oxygen, carbon dioxide, nitrogen, ammonia and chlorine. Some of these gases are poisonous while others are necessary for fish to breathe. Water also contains dissolved minerals that determine the general hardness of your water. Some fish thrive in very hard water with a high ph, while other fish prefer much softer water with a lower ph. Organic matter can also dissolve in the water, usually darkening the water and acidifying it.

A biotope should include a substrate, plants and a source of light with the temperature of the water kept within a suitable range for the plants and fish. The choice of subrate includes gravel, sand, and even soil. Soil is usually topped with gravel. Other less essential features you might want to include in your fish’s biotope could include rocks, roots and branches.

The Lake Malawi Biotope explained here

The Amazon Biotope explained here

Is tap water safe for fish?

Is tap water safe for fish
Is tap water safe for fish

Tap water direct from the tap is not suitable for use in an aquarium. The main problem is chorine which water companies put in the water to kill off any potential bacteria in the water. To remedy this you need to leave your tap water standing in a container for at least 24 hours. This allows the chlorine to evaporate. This can be achieved by using buckets of water or water barrels to store the water.

Another danger to your fish is from dissolved copper which can come from copper pipes. Water that comes into contact with copper will slowly absorb the copper. This problem is worse for new copper pipes. But this can be remedied by running your tap water for a few minutes until uncontaminated water starts to come through. Copper is poisonous and even copper coins left in your aquarium will slowly dissolve and kill your fish.

If you are going to be serious about the quality of your fish’s water then you should buy a water test kit. A good test kit will test ph, ammonia, nitrite and nitrate as well as general hardness.

If you are a new fish keeper who wants the best chance of keeping your fish healthy and alive then test your tap water before you buy any fish. When you know the ph and hardness of your water then you can buy fish that prefer the water from your tap. Adjusting your water to suit fish that like a different type of water is best left to the advanced aquarist who don’t mind the extra effort. Some fish when kept in the wrong type of water will simply die after a few weeks and certainly won’t thrive.

If you are a more experienced aquarist then you can start adjusting the ph and hardness of your tap water so that you can keep the more delicate species of fish. To soften your water you can buy a reverse osmosis device that will remove the minerals from your water. Such water is usually too soft and must be mixed with unfiltered tap water to achieve the correct level of hardness. You can also use rainwater collected from a safe source.

To adjust the ph of your water you can either use a muslin bag containing peat moss to acidify your water or you can use calcium carbonate sand to alkalinify it instead. In order to reach the correct ph level.

All these procedures are complicated and time consuming and even prone to error. Messing with your tap water usually means you will have to monitor changes in your water conditions to maintain it. To make this complicated process a little easier it is best to prepare large batches of water in say a 200 litre barrel all in one go and then draw off water as needed.

I recommend that you don’t bother with all this messing around and just buy fish that can do well in the water that comes from your tap. There is usually quite a variety of fish that will suit your water conditions but you may have to avoid a particular species of fish that you might be keen on.

What water conditions are best for fish?

Normally the ph used in most freshwater aquaria ranges between 6.0ph and 8.3 ph. However Lake Tanganyika fish like an even higher ph, even as high as 9.0ph. And they also like hard water. Ph nearly always varies together with hardness. High ph above 8.0 usually means very hard water, while low ph of 6.4 or less coincides with soft water. Some amazonian fish like water that is of a ph less than 6ph and have very soft water.

Most of the commonly available fish in your aquarium prefer an average ph around 7ph and a medium level of water hardness. Not only that but such species can also tolerate a wider variation away from this medium than other more exotic species. Tank bred fish that have been bred in aquaria for several generations are overall more adaptable to variations in aquarium conditions compared to their wild caught counterparts.

Most average species will live in a wide range of possible water condititions. However, when it comes to breeding the ph and hardness must more closely resemble the fish’s conditions in the wild. Only then will some fish be capable of breeding and their eggs hatching.
Water hardness

This is a measure of the amount of dissolved minerals in your fish’s water. The most common minerals are calcium, magnesium and sodium.

These dissolved minerals are also essential for the health of your fish and plants.
Most cyprinids, tetras, rasboras and similar river fish like soft water. Most livebearers, Malawi fish and Tangayikan fish prefer quite hard water.

Plants also show a similar type of preference for different levels of hardness depending on the plant species.

Iron for fish health

Plants require minute levels of dissolved iron for optimum health as do fish. Fish acquite iron from their diet while plants will absorb it directly from the water. Pure iron quickly rusts in water making it unusable for the plants and animals. Feeding fish iron rich fish food will not only provide iron for the fish but allow the fish to provide manure that is rich in iron for the plants use.

Dissolved oxygen in water that fish breathe

Dissolved oxygen is essential for fish to breathe. The main source of oxygen in an aquarium is through the surface of the water. So a large surface area of water is essential to allow sufficient oxygen to dissolve into the water to replace the amount of oxygen that the fish breathe in through their gills. Also excess carbon dioxide that the fish release into the water from their gills has to be released from the water through the surface of the water. Plants also give off oxygen when they are in bright light, but will release a small quantity of carbon dioxide at night.

It is best not to rely on the quantity of oxygen that plants produce during the day to supplement the amount from the surface because this source of oxygen stops at night. If you see your fish gasping for air very early morning this is a sign that there is not enough oxygen and too much carbon dioxide in the water in the night so you will have to reduce the number of fish in the aquarium. This can also be a sign you have too many plants.

Fish waste in water

One lethal cause of fish deaths is ammonia poisoning which burns the skin and gills of the fish while also displacing oxygen in the water. Ammonia comes from fish waste and from decaying fish food and other decaying organic matter. In a new aquarium there will be no ammonia but this will build up over the fish few weeks. If you are new to fish keeping you will see your fish as being fine for the first week and may not realised that the fish are slowly but surely poisoning themselves in their own waste matter.

To overcome this you need some way to remove the ammonia as it gets created. You will have to for the first 6 weeks have to do daily water changes, use a filter and make sure that you under stock your tank until it is mature. Also avoid any uneaten fish food being left in the tank that will quickly rot and cause an ammonia spike.

A filter is not just for removing particles from the water but also for providing a base for the growth of bacteria that digest ammonia converting it into nitrite which is also poisonous. Later on another set of bacteria develops that will digest the nitrite converting it into nitrate which is much less harmful. This process takes between 4-6 weeks from new. So partial water changes are needed daily until the filter matures.

This is better explained in cycling your aquarium

Plants take up nitrate but usually not enough so you will need to keep doing partial water changes, perhaps once a week. 10% of the water changed is a reasonable amount of water change.

During this filter maturation period you should test your water daily with a test kit and if the ammonia or nitrite reading becomes particularly high then you will have to do another partial water change to bring it down to acceptable levels.

Amazon biotope aquarium

amazon biotope with angels rummy nose and rams

Introduction To The Amazon Biotope Aquarium: Recreating The Amazon River

amazon biotope with bolivian rums and rummy nose tetras
amazon biotope aquarium-Bolivian rams and rummy nose tetras

One of the more popular options when it comes to biotope selection is the Amazon biotope aquarium. This is a setup that is designed from the ground up to emulate the conditions of the Amazon River, and, if done right, will give you a unique insight into the ecology of this fascinating part of the world.

While keeping a biotope aquarium of a tropical river with such diversity may seem like an expert-level challenge, the truth is that beginners looking to set up their first Amazon biotope aquarium have little to fear if they do adequate research and make the right choices. If approached correctly, the Amazon River can be a very accessible biotope choice.

Also Malawi biotope here

Getting started on your amazon biotope aquarium

Despite its apparent complexity, the Amazon River environment can be relatively simple to replicate. The key is making practical choices concerning the accuracy of your biotope aquarium: The Amazon River is full of undesirable predators, leeches, and parasites among many other qualities that are detrimental to the aquarium environment, so you will need to make some compromises.

These issues do not stop at aquatic predators, but go on to include dark, muddy water conditions that offer very little visibility and a thick soil bottom that would be impossible to clean. That will not only make your tank plant-less and barren due to the lack of light penetrating the water, but will also make it difficult for to you enjoy seeing your fish at all. In general, you are best advised to avoid trying to create a 100% faithful biotope aquarium.

amazon biotope with angels and roots
amazon biotope with angels and roots

You can, however, make great strides forward in your plans to keep an Amazon biotope aquarium if you combine some effective aquascaping with common sense ecological accuracy. The best way to do this is to scan the Internet for images of Amazon biotopes that you like the look of and then work towards your own expression of that example. Once you have a clear idea in mind, there are three basic methods to approaching your biotope aquarium:

• Find the fish that you like, determine what part of the Amazon River they are from, and then create the biotope to suit them;
• Choose a specific part of the Amazon River to replicate and fill your tank exclusively with fish from that area;
• Begin with the plants, driftwood, and substrate and then build your tank upwards from there.

Either one of these methods can produce a successful Amazon River biotope aquarium if handled correctly. You need only choose which elements you are most comfortable starting with.

Types of amazon biotopes

Since the Amazon River is so large, there are a number of options from which you can choose when it comes to your specific type of tank. Some biotope options will be very different from others, and more ideally suited to certain species that would naturally live there. A short list of options include:

• Whitewater Stream—This environment features water with a slightly muddy appearance. Whitewater tanks look their best with driftwood and dead branches added in, as well as a dark sand substrate.

• Blackwater Stream—Waters that originate deep within the rainforest and contain a high level of dissolved leaf litter are usually referred to as blackwater streams. This water is more acidic due to the dissolved leaf litter that you will need to add, or even use as a substrate.

• Oxbow Lake—This refers to the many crescent-shaped lakes that form when the Amazon River changes course. These lakes tend to be both muddy and filled with accumulated leaf litter and debris. For this reason, mud is an ideal substrate, and Oxbow biotope keepers will want to keep filtration to a minimum.

How to simulate amazon river water

The acidity of your Amazon biotope aquarium will vary depending on which of the three above choices you choose for your tank. For example, a whitewater river environment will require water with a pH level between 6,3 and 7,0, while a blackwater biotope will be more acidic—between 4,5 and 6,5, and the Oxbow Lake water has a pH between 5,4 and 6,8.

The temperatures of the various forms of the Amazon biotope aquarium tend to be less varied, with 24-28° C being the norm. Water hardness should be kept reasonably low, as most of the dissolved materials in Amazon waters are not mineral, but organic: a dH level between 3-8 should be ideal.

When it comes to attaining the signature colouration of Amazon water and keeping the fish as comfortable as they would be in the wild, it is necessary to mix peat with your reverse osmosis-filtered water as well as some leaves to give it substance. Examples of leaves that will help create the tannic water commonly seen in the Amazon are:

indian almond leaves
indian almond leaves

• Indian almond leaves,
• Oak leaves,
• Copper beach leaves.

The idea is to stain the water using these leaves in order to give it the unique brown appearance that every Amazon biotope should have to some degree. The other main element of your biotope water will be peat.

Peat is widely available from aquarium supply stores and fish shops and is necessary for gaining the correct level of dissolved organic matter in the water and reproducing the Amazon River environment correctly. In order to maximize the benefits of peat, it is recommended that you do not use with activated carbon filtration or with waterborne fish medicine.

Peat is a unique element of the Amazon river environment and one part of your biotope that cannot be skipped. Your Amazon biotope aquarium tank should be cycled with peat present, and topped off if the water gets too clear after changing later on.

Populating your amazon biotope aquarium

amazon biotope with angels rummy nose and rams
amazon biotope with angels rummy nose and rams

The Amazon River is home to an enormous number of different species, and some of them are better suited to certain tanks than others. Naturally, you will want to choose species that do not prey on one another and that can live in relative peace and harmony in your tank—this can be tricky when it comes to Amazon fish.

One of the main aspects that you will want to take into consideration is the size of your tank. If you plan on keeping a small tank, then basing your Amazon biotope aquarium on a population of tetras or dwarf cichlids would be a great idea, while larger tanks can afford to support more exotic options.

More on tetras here

More on dwarf cichlids here

If you have a large enough tank, you can populate your tank with Angelfish, Silver Dollars, or even piranhas. Care must be taken with larger community tanks keeping these kinds of fish, as most of them are very aggressive. Often, aquarists will stick to a single species in order to minimize violence between fish—and even then the tank is not guaranteed to be 100% violence-free.

Considering plants for your tank

Plants, too, must be considered in light of the unique water conditions that the Amazon River provides. The main issue here is that the standard water conditions of the Amazon offer very little light penetration. Some flexibility on your plant choices here can help a great deal in the long run. Some plants that would be at home in this biotope would be:

• Echinodorus (Amazon Sword, Dwarf Sword, etc.);
• Hair Grass;
• Cabomba;
• Myriophyllum.

One of the major concerns for plants in an Amazon biotope aquarium is access to light. If your water features a high level of dissolved organic material like it should, your plants might not have adequate access to regular aquarium lights, requiring you to get more powerful ones for them. Cabomba and Myriophyllum plants, in particular, can present problems from this point of view.

Another concern when it comes to aquarium plants in this environment is the number of plants to keep. That level of dissolved organic material in the water will make algae control a challenge—keeping lots of plants will help balance your tank and keep it relatively clear. Again, if you choose to be flexible in your plant choices, you can benefit from a healthier aquarium even if it is not 100% faithful.

Aquascaping and driftwood

mail order driftwood is suitable for amazonian biotope
mail order driftwood is suitable for amazonian biotope

While you may have all the information you need to begin your new Amazon aquarium, creating a natural-looking Amazon river environment requires that you take the time to plan your tank out carefully and find the right décor for it.

Driftwood is an essential element of a faithful Amazon biotope aquarium tank. If you have a larger tank and would like to keep one or two panaque catfish, you may even need to provide driftwood as food for the fish. Trying to source natural driftwood from the actual Amazon River is a futile task for most aquarists in the world—instead, you will have to find suitable wood from other sources.

In general, clean bog hardwood that has been carefully dried out can be used in your aquarium. You will want to introduce the wood before the plants and fish in order to compensate for any water quality issues that may occur.

Putting together your tank with all of these separate elements will take some planning and forethought. If you have taken the time to look at other aquarists’ Amazon biotopes, you might have a good idea of where you want to go with yours. Another option it to find genuine photographs of the Amazon river and to use the materials at hand to replicate the aquascape to the best of your ability. Both of these are equally suitable methods of making an ideal Amazon biotope aquarium.

When you have completed your aquarium it is worthwhile going back to the original images to see how closely you have replicated the original biotope image. Perhaps you have surpassed the original and can relax. Or, perhaps you have forgotten some element that would add the finishing touches. When all is complete you can then sit back and enjoy your small simulation of the amazon river. After all this is what all the effort is all about.