I think, therefore I harm
In the first part, I explained considerations concerning a first fish tank. Now, let’s see how to set up your aquarium and launch it. This article does not want to address every issues in deep details, but wants to help you getting started while avoiding the common mistakes novices do.
Before setting up an aquarium, you must absolutely test it for leaks. It doesn’t matter if it was bought new or used, all tanks may be defective or get damaged during travel. No amount of leaking is acceptable, not even a drop a day. Once your aquarium is started, it may be difficult to notice leaks, and if a leak is discovered it may be extremely difficult to take care of. Do not skip this step.
If the aquarium comes in a box, put it on the floor, ideally not far from the bath – you will have to empty it later. Tear the cardboard around the aquarium rather than take the aquarium off the box. You will never use that box again and it’s not a good idea to pull the tank by holding the top or the sides, therefore it’s a lot easier and safer to just tear the box apart. Just leave the tank on the cardboard. If there is polystyrene foam under the aquarium, take it off. If the aquarium doesn’t come with a box, I like to put white sheets of paper underneath, such as a thick layer of scott towels. In any case, you want a way to detect small leaks, which will not be visible if you leave the tank directly on the floor.
Put just a small amount of water at the beginning, just enough to cover the bottom, and check for any obvious leak. Pay attention not to accidentally spill water near the tank, which might be confused for a leak, or prevent you from detecting leaks. If you are satisfied, add more water, and keep looking for any obvious leak. Usually, I fill about a third of the tank and leave it alone for an hour or more, and check the cardboard or paper for any sign of a leak. If everything is fine, I fill it another third and wait again. Eventually the tank is filled completely. Leave it there for at least 24 hours, ideally 48 to 72 hours, and check regularly for any leak. Do not fill the tank and immediately go to bed, a leak might become apparent during the night and provide for quite a bad morning. Make sure you have a few hours ahead before starting the leak test.
Before you put the aquarium on the stand, it must be perfectly leveled. Use a level tool, either electronic or the good old bubble level. Do not trust your eye. I have yet to see a leveled floor, so you will need to make adjustments. Do like the pros, and get these sticks that you get for free in hardware stores to mix paint. I like to break them in three pieces, with my bare hands. Pile as many as necessary to level your stand, pushing them underneath the stand feet. When you are done, check that you would be comfortable dancing on top of the stand. Do not actually dance on it.
Do not put the aquarium directly on the stand. Even though you chose a good quality support, it may still bend a little or move over time. Remember, your aquarium will likely stay in place for several years, it’s better to plan ahead. To absorb any such deformation of the stand, it is suggested to put a layer of polystyrene foam under the tank. This will help diminish the impact of a surface that is not perfectly flat, even if it is not visible to the eye.
For smaller aquarium, you could cut a piece out of an exercise mat, the kind that you roll when you store it away. I found these were surprisingly expensive though, and I found a better and less expensive solutions. They sell polystyrene foam flooring tiles that you can use in areas of the house where you frequently stand, such as the kitchen, for comfort and safety. These are available in most department stores. They are sold by individual tiles, or in packs of four or such. You can assemble two tiles or more to cover your surface, and cut any excess with a knife. Leave a few centimeters / an inch around the aquarium, as the ends of the mat will curl up when you fill the tank with water (it gets heavier); do not cut the mat to exactly the size of the tank.
There are quite a few pieces of equipment that will need to be plugged in. I always install a power strip on one side of the stand, at the very top of it. It serves several purposes. It will let you have more outlets. You can turn off all of your equipment at once, if something goes wrong or for cleaning. By putting it high, it forces a drip loop on every cable.
Now is the time to put the tank on top of the stand (make sure you emptied it before moving it). Before settling it into its permanent position, take a minute to clean the back glass; you will never get another opportunity. Check that the tank is perfectly leveled – if it is not, readjust the stand, not the tank itself.
Most people prefer to fill the substrate first, and then the water. Others like to put a small amount of water first. Do not wait until the tank is completely filled with water though. You will need between 1.5 and 2 pounds of substrate for every gallon of water. This is a rough estimate, of course, make adjustments based on whether the tank is wide or high. 3-5 cm / 1.25-2 inches is fine. If you want plants, go for a thicker layer of substrate. It may appear like a lot at first, but you will soon realize that there is never enough.
Colored gravel sold in stores is perfect for a first setup. Most people prefer a darker color substrate so the fish colors appear brighter. Furthermore, fish seem to prefer darker substrate. If you intend to keep plants, you may want to use a smaller size gravel to hold the roots better.
Sand has became popular as substrate, in particular in saltwater. It is believed to be more efficient for bacteria. However, there are many risks associated with sand, and sand is therefore not recommended for beginners. Sand cannot be cleaned as easily as gravel. If not cared properly, it could accumulate debris which could turn into toxic gas which could kill fish. Also, sand can obstruct your filtration system. It’s better to get informed before you settle for sand as substrate.
Fill in your tank with tap water. Most people like to fill it just enough that the surface line is hidden behind the top ring or border. You may want to put a little less initially so as to not spill water as you proceed with installing your equipment and decorations.
Install your filtration system – read the instructions that came with it – and turn it on. You should also install your heater, if you intended to use one. You may also put any decoration.
You may also install your lighting, but you may want to leave it off during the initial cycle. Light is not beneficial at this stage.
Now, wait a month.
An aquarium is an ecosystem. A large amount of bacteria will work in there, their task being to decompose things, such as fish poops and extra food. From these trash, bacteria produce good and bad chemicals. Bacteria are desirable and part of a normal and healthy aquarium.
You must give bacteria time to develop. This wait time is called the nitrogen cycle, or often just the cycle. A cycle normally occurs only once and lasts about 3-4 weeks in a new freshwater aquarium, and up to 6 weeks in a saltwater aquarium. In the middle of the cycle, the level of toxic chemicals in your aquarium will be very high, which would kill most of your fish. You must not put anything alive in your tank until the end of the cycle. Loosing fish during a cycle is a novice mistake that we often refer to as the new tank syndrome.
The nitrogen cycle is quite simple to understand without going into advance chemistry. Everything that gets decomposed is turned into ammonia, and then into nitrite, and finally into nitrate. Each step is performed by a different set of bacteria. If you were to regularly test water with test kits, you would see a peak in the level of each of these toxins, in order, a few days apart, with the ammonia after about 10-14 days in freshwater or 14-21 days in saltwater.
You must perform water changes and clean your filter regularly during the cycle, even with no fish.
Waiting a month is usually safe enough, but for extra confidence you can buy a nitrate (NO3) test kit. Your bacteria colony is ready when the test shows no trace or very low level of nitrate. At this point you can begin introducing your inhabitants, but do it slowly.
It is common to get a small algae bloom during your cycle, or soon after, but don’t worry as it should not last longer than a week or two.
Products are sold on the market to get rid of the cycle. Often designated by hobbyists as bacteria-in-a-bottle, their efficiency vary by brands and users. Some people claim to use them and be able to put fish in the tank immediately, claiming to never have a nitrogen cycle. Others use them as helpers during their normal cycle. Many more wouldn’t approach these products with a pole. I tried two different brands in two different occasions, as a helper, and didn’t get any appreciable result. Your experience may vary.
If you intended to get plants and snails, introduce them first. Wait about a week before going with your first few fish. Each time you introduce something new, you will break the balance of your ecosystem. Your bacteria will quickly adjust to the change though, but this period is often called a mini-cycle as there may be a small increase in toxins. You can always use a nitrate test kit to check for any such development. Do not add too many fish at once.
Most people perform a partial water change once a week, or every other week. Every aquarium being different, you will have to learn how much maintenance your aquarium needs. Test kits are handy, especially in the early months, to see how the parameters evolve over time, and see what seems to be a good frequency for your particular tank. If all of your snails are at the top of the glass, desperately fleeing the water, than you need to perform a water change. If you have frequent algae blooms, increasing water changes frequency may help.
Do not ever completely empty the tank. Your mother did that for your goldfish bowl, but an aquarium doesn’t work like that. A normal, regular water change should not be of more than 10% of the total water volume. If you have nitrate problems, or if for any other reason you were told to perform a larger water change, you may go up to 20%, but that should only be on these rare occasions. Removing too much water is not good for your ecosystem.
Do not put fresh water right from your tap right into your tank (except for the initial filling). Tap water contains chlorine, which is added by your water utility to prevent algae and bacteria from developing in the pipes, and it will damage your ecosystem. Chlorine evaporates in about 24 hours, therefore you must leave water to rest for at least that long. The common recommendation is 48-72 hours. If you are in a hurry, chemicals are sold that will get rid of the chlorine in a shorter time. I let a 18.9 L / 5 gallon bottle to rest at all time which I fill again after any water change. As an alternative, you may use bottled water, which does not usually contain chlorine. You should be aware though that the amount of nutrients in bottled water is often lower than tap water, and as such it should only be considered if your tap water is not of very good quality. If you don’t know how to test your water, or do not own test kits, bring a sample to your fish store which will perform the analyses for a low fee ($20 or less) and give you recommendations.
For saltwater tanks, most people prefer to use distilled or osmosed water, either bought from a store, delivered, or prepared using home water purifying equipment. A suitable RO/DI (a reverse osmosis device) can be bought for $200 new, or $100 used (assuming new filters). In any case, salt must be added to the water and let to dissolve for about 24 hours before the water is added to the tank. In my case, I have saltwater ready at all time, which I prepare from bought osmosed water.
While you perform your water change, take the occasion to do some cleaning. You can clean your filter media in the water you just removed. You can clean the inside of the front glass – I never clean the other sides, I leave whatever grows there, it looks more natural, plus it feeds your snails. You can clean your substrate occasionally, but not too often, as it disturbs your bacteria colony.
Filter media contains an important part of the total bacteria colony. Cleaning them in the water you just removed works well because it minimizes the loss of bacteria. Do not clean them under running tap water because you would kill the bacteria with the chlorine in the water.
Filter media manufacturers most usually recommends changing them every month. Unless your aquarium is particularly dirty, you can get away with changing them less frequently. In most cases, changing them every three months is just fine. If there is a lot of visible detritus that cannot be cleaned off, or if the water becomes visibly less clear, it would be a good time to change them. Since the filter media hold part of the bacteria, you should not change all of the media at once. Instead, you should change a different one every month, until they were all changed, and then repeat the cycle.
Obviously, this is just a basic introduction. Do not think you know everything by now, but you should be comfortable with the basics. From this point on, you may want to buy a book, read more on websites, and even subscribe to a forum.
Feel free to ask any question, add in your experience, or express opinions in the comments below. I do not plan on bugging you any longer with posts about fish tanks, but if I get suggestions or a general interest, I may just as well write more in the future.
I recently found this blog, Cassie ~ Jux.ta.pozed which, among other things talks about fish a lot. From her own words, she is a specialist, not a generalist. She has articles about specific species of fish, but also a few about the nitrogen cycle and water parameters.