Any person who has an aquarium with fish or herbs in the house knows that it is necessary to clean the container periodically, otherwise, it will collect food and animal waste, which is not only unsightly but can also damage the lives of the swimmers.
Thus, it is imperative that water is always clean and clear, and to find out how to create a favorable environment for fish, it is enough to pay attention to the many opinions about the best aquarium filters. The dirt deposited generates ammonia and nitrites, two toxic elements that affect invertebrates.
Their effect is controlled by the action of the filter, which will enrich the flow of oxygen and help create beneficial bacteria for organisms that will turn toxic particles into less harmful ones.
These devices can also collect metallic and chemical substances, ensuring the health of the ecosystem and, at the same time, decreasing the frequency of water change.
Things to Consider Before Buying an Aquarium Filter
For those who are already interested in finding good quality aquarium filters, we can give them information on this, but first, we will present some essential aspects that need to be taken into account before making a purchase.
The existing models, the ways in which they can work, the right dimensions and the costs are some of the features that you will be clear about after following the shopping guide.
It is done through three methods: mechanical, biological and chemical. Devices can use only one filter or all, the latter being the most effective and recommended. Additionally, if one of the facilities fails, you will still be able to use the other methods without the need for new investment.
Mechanical uses synthetic filters (foam or silk) that collect visible particles and deposited remnants.
Biological is achieved by increasing the volume of oxygen in the aquarium. In this way, an environment conducive to the appearance of beneficial bacteria, which convert waste into less toxic ones, is formed.
The chemical uses active carbon and resins to extract harmful substances and pollutants from the liquid. The advantage is that it will clean all the particles, even those that can not be seen with the naked eye.
Types of Aquarium Filter
Depending on the place where the products are disposed, there are two main categories: external and internal. Devices in the first category have higher prices, they are visible and occupy more space, but they are also the most effective.
Interior items are smaller in size, more accessible and easier to fit, but are more prone to get rid of residues, requiring more effort for maintenance.
External devices are obviously placed outside the aquarium, they are bulky, noisy and suitable for medium and large containers. They pump the water inside and eject it through a pipe or pipe system. There are three external models: the canister, the waterfall, and the wet/dry type.
The canister is connected through inlet and outlet tubes, where the first collects the water and leads it to the vessel where the filtration takes place, and the latter drives the clean liquid back into the aquarium.
This action is accomplished by means of a pump, and the advantage of the item is that it has high flexibility because it allows you to place it in any place around the pool. It also takes into account that their price is higher.
The waterfall type hangs on the back of the vessel and is also connected through tubes. This is among the most affordable and versatile, as it allows all types of filtration, and the mode of operation is very simple: a centrifugal pump collects the dirty water, leads it to the treatment chamber, and it is pushed back through a spillway.
The wet / dry one includes an overflow chamber and a tank fitted with the pump. Filtration is achieved through a mixture of water and air, which stimulates the production of beneficial bacteria, maintaining an optimal level of oxygen in the pool. Their price is higher and you may need help in setting it up, but the item is also among the most effective.
The internal devices are quieter, cheaper and, as can be deduced from the name, they are caught by the suction cups by the inner walls of the aquarium. By means of a pump, the air currents are put into motion, forming bubbles strong enough to allow filtration. And these, in turn, are found in three patterns: those with a corner, sponge, and substrate.
The one on the corner uses compressed air in the filtration process, which is pumped to the bottom of the bowl to rewind the dirt. It does not occupy much space, is accessible and easy to install, and is easy to maintain, as you can pick up the item and clean it separately, then place it in the pool.
The sponge, in particular, performs biological filtering, and toxic particles can be extracted manually. The dirty liquid is also withdrawn by a pump, but the risk of locking and clogging is higher than the other models, so it must be removed more often from the water and rubbed from the residue.
The substrate allows biological and mechanical filtration through a plastic barbecue that is placed between the bottom of the aquarium and the sand and gravel layer.
An air pump or internal filter extract residues and cleans water. It is recommended for medium and non-crowded vessels. Planting is avoided, as its root is affected, but if you insist to decorate the aquarium with it, it is better to put the plant in pottery pots.
It is conditioned by the volume of the aquarium and its density. A high-flow filter is suitable for large vessels, and in this case, an external product is best suited.
For example, at a volume of 50 liters, the filter should have a flow of 60l – 100 liters (it can be 50 liters, especially if it is not very populated, but no less).
Moreover, a large number of fishes means more waste, so the item needs to be as large as possible. For very wide containers, you may need both types of filters or at least two of the same category.
The ease with which this is done depends on the model. An external appliance is easy to maintain, and the cleaning can be done every two or three months.
An intern, however, gets in constant contact with the dirt and must remove it from the pool when it is washed. To minimize this effort, look for a product with pre-filter function.
They are proportional to the performance of the item. But if you do not want to invest a lot, when you are looking for where to find other aquarium filters at a good price, you can stop on an internal product (these are more affordable).
Also, you do not have to buy an expensive filter if you think you will want to change the pot with a larger one in a while. However, try to stay with a trustworthy producer, as you will take your money in the long run, because the risk of the device spoiling is less.
In conclusion, buying a filter is mandatory for all who own an aquarium, but the one that’s right for you remains at your choice.
Buying something from the Internet can be an inspired option that we recommend. Not only will you find more deals than conventional stores, but you do not even have to go and, moreover, have the opportunity to learn about the experiences of other users.
Best Aquarium Filters
Below, you will find a list of the most popular aquarium filters available right now:
1. Penn Plax Cascade Canister Aquarium Filter
This filter is made for freshwater as well as for saltwater fish tanks. This wide range of products is why so many love this product and are loyal to it. Different types of aquariums in up to 200 gallons are available in this canister filter.
The product provides a remarkable water flow of 350 gph during operation. Just ensure that you maintain it well so that it works effectively and efficiently.
With a simple button press, the product can easily begin and it has a rotation of 360 degrees to better filtrate the tank. With a big filter tank, you can use the system long before the substitution is required.
It is a trustworthy speed that you count on when you hurry. Do your fresh and marine aquariums need clear water? Well, this fish tank filter comes with a cleaning process of 3 stages; for perfect work the mechanical, biological and chemical filtration.
The floss pad is highlighted to remove toxin and impurities from your water, to make it more clean and sanitary for your fish and any other aquatic life, by its activated carbon media.
2. Fluval Canister Filter, FX6 Filter (400 Gal)
When the canister is filled with water, the filtration system is automatically started. To start the product, no water siphoning is necessary.
It has a drain on the base of this model. The purpose of the valve is to help empty the canister, making it easy to maintain. In order to send several streams of filtered water to various corners of the aquarium, the spout attached to the system can be modified.
The intake of the box is wide and circular and this function helps to siphon more water into the box faster.
The FX6 uses six stormy filtering stages! Each basket was designed with precision to stop the bypass of any water. This results in an efficient process of filtration.
The maintenance is very easy and if you are the type who is not the best person to keep up with your maintenance. The monthly dial will help you keep in mind the exact date of your last maintenance and change in water.
The FX6 of Fluval is a filter beast. It’s a top filter system in the aqua technology cutting edge. You could rely on this filter for a very long time, durable and reliable.
3. Fluval C Power Filter
The Fluval C4 Power Filter is a rear-mounted filter which works as a filter box. It has a modular media section design, which allows one part of the filter to be switched off or cleaned and it holds much more media than other HOB filters. It’s also easy to customize your own media with its modular design.
The C4 features a five-stage filtration system (two mechanical, one chemical and two biological) for the selection and filtering of particles.
This filter can produce extraordinarily clear water together with a high flow rate that keeps your fish healthy and happy.
4. Marineland Penguin Power Filter w/ Multi-Stage Filtration
Not everybody needs or has a budget for an aquarium filter that is as powerful as our top choice. The quality may not quite conform to the standards of our number one choice, but for tanks with up to 80 gallons, it provides simple and efficient filtration.
The Marineland E Rite-Size Filter cartridge is included, but you can use your own selection of media if you prefer, or add additional media to suit your needs. This filter is also equipped with a biological filtering “Bio-Wheel.” This takes your filter’s life and must never be changed.
5. Fluval External Filter
This model filter offers superior filtering. It is ideal for all sizes of aquariums made by different producers and works for freshwater or aquariums with saltwater.
The powerful engine technology helps speed up the process of filtration. These different features make this product much better than its competitors. To make the product functions as required, you simply need to follow the simple set-up instructions.
This product works calmly, with fewer vibrations than other filters for those who are concerned about noise. The multi-stage filtration process promises high quality and cost-effectiveness.
6. EHEIM Classic External Canister Filter with Media
The product has a ring that holds the product tightly screened while working in the aquarium. You don’t have to worry much more about the leakage with other fish tank filters that are reported to occur.
This filter is fitted with filter sponges and other loose filter media, making it easy for the product to work. The device includes many accessories, such as a spray bar, hose, pull-in and many more.
Enjoy a constant circulation of water and an improvement in systemic oxygen during the water purification. Enjoy your fish in filtered waters with the easy-to-use compact size of this fish tank filter with a complete stand in a healthy environment.
You can easily find the silicon ring on the head of the pump during the closing after cleaning your aquarium. It can be transported easily and lightly, saving time for the most quickly filtrated aquarium process.
7. MarineLand Magniflow Canister Filter for Aquariums
This is the right fish tank filter for you if you are an enthusiast of the wide tank filter cleaning. Enjoy your multi-stage filter with stackable tables that are easily breakable to ensure that you do have good maintenance and care.
Do you handle filtering in medium or large aquariums never have to concern yourself? It is a dedicated and ready tank with your favorite fish species to hit the waters up to 75 gallons.
Create a large saltwater fish community with a reliable water filter, that meets your expectations and cleanses the water thoroughly, allowing the fish to thrive comfortably, not just crystally clear.
Do you have a large aquarium up to 30 to 150 gallons? You need a filter for the fish tank to clean a walk through the park. This is exactly what is emphasized in this filter to supply you with every cleaning cycle.
8. Aqua Clear – Fish Tank Filter – 60 to 110 Gallons
You want a superb fish tank filter with an efficient filtering process as it takes enough time to contact the filter media.
Expect to reduce, thanks to its efficient energy pump, the long-term operating costs for this fish tank filter. Save your time when you install the filter as quickly as possible.
This model is equipped with AquaClear foam, bio max and cycle guard, activated carbon for the smooth functioning of its biological filtration while it carries a guarantee of 2 years. This makes this model one of the highest quality water in comparison with conventional brands.
If you have an aquarium of 110 gallons, filtration with the fish tank filter is an easy task. It’s never necessary to find this model boggling. The ultimate fast installation is a feature that can be seen in its user-friendly handbook.
Just plug it in your aquarium water after you have prepared your filter for comfortable use. Customize the water flow with its medium level strainer to your preference.
This does not only make the installation easy for you but also time-consuming. Recall that your filter cartridge is removed and replaced monthly
9. Hydor Professional External Canister Filter
Easy to configure and easy to use. Three times you’re ready to go, tap the self-printing button! The engine is durable and soundproofing that makes it silent.
The rectangular form ensures that the filtering process is very efficient. Every tray has a large volume of media, it is flush against the sides completely. This forces the water without circumvention through the filtration media.
All necessary media are included with the kit, except carbon. You get space for 2-5 media trays that allow the multistage filtering process depending on which size filter you choose.
They are designed to reduce back pressure using ball-valve connections. And you can adjust the water flow effectively so that you can have the perfect output for your tank.
When you remove your filter for maintenance, you can shut down the flow.
It has an expandable spray bar, which is cool about this filter. You can adjust the length and position of your tank in the four sections to achieve the best results.
The spray bar allows the water flow to be spread and moved into more areas of your tank.
10. Penn Plax Cascade Hang-on Aquarium Filter
The filter is a heavy duty fish tank that guarantees high quality and durability in exchange for costs. This product can pump 265 gallons per hour, mainly used for aquariums of 100 gallons.
It is designed to perform powerfully even for long periods of continuous use. You can expect crystal clear water to be delivered to marine as well as freshwater aquariums through this filter system.
The product comes with a ground sponge which removes waste and excess food efficiently from the fish tank.
11. Tetra Whisper Power Filter for Aquariums
Take this 1.3-pound fish tank filter for your special aquarium filtration seriously, especially for small-sized aquariums, because it offers superb performance.
Compare this filter to do an excellent job for 20 gallons of water while you take the best time to filter your tank.
Removal from your aquarium of the excess food, organic decay, dangerous chemicals and intelligently mounted suction cups or brackets which help to quickly remove waste, saving your time.
The filter uses large whisper cartridges with an organic whisper for the intelligently designed three-stage filtration process, emphasized for a clear cleaning that will make your fish more caring and reliable aquarium maintenance enthusiastic.
This is not only the right choice for those of us who love filtration, but also for flexible adjustment of low or high water levels.
12. Sunsun Hw304B 525GPH Pro Canister Filter Kit
The fact that it comes with a built-in 9 watt UV sterilizer is what makes this filter stand out. This helps kill bacteria and algae spores; it supports crystal clear water.
The large blue automatic pump works great and avoids the need for manual siphoning. And with four flexible media trays, excellent mechanical, chemical and biological filtration is achieved.
Cleaning and maintenance are very easy, but when cleaning, one thing you must take into account is the order of the racks or the top is impossible.
It is possible to untie both the input and output tubes at the same time using a useful switch.
In fact, the switch cuts off the water and leaves it in both sides. It’s useful because it’s going to help you restart your siphon system.
It is necessary to be aware that the flux rate is not controlled by this switch. Stick to it or open it.
The SunSun Pro can stand by the big names and save you a lot of money. You’re getting a lot of power and it’s resistant and the motor is running efficiently.
How to use an Aquarium Filter
An aquarium is a small oasis of relaxation – if it has not already turned into a passion. It’s hard to conceive today a functional aquarium without the help of a filter, but there are a number of tricks that you need to be aware of because the action is the one you expect.
Assembling the Filter
For space-saving reasons, many manufacturers deliver disassembled filters, and it is your job to mount them before you can install them in the aquarium.
Generally, the assembly information is so detailed that it should not encounter any difficulties during this process which, however, takes only a few minutes. Start by identifying each piece, then the connections between them, and then just go to the actual installation.
Install the filter
Once you’ve made all the connections between the filter and the rest of the aquarium water purifier, it’s time to actually install it.
In the case of filters placed under gravel, make sure they are positioned correctly, including the piping, before filling the container with water. Also, check that the piping is properly attached to the air pump.
In the case of external filters, mounting is often simpler and installation easier, the main concern, in this case, is that the power supply does not come into contact with water.
Cleaning the filter
Apart from the exceptional situations in which the aquarium is particularly dirty, the monthly cleaning of the electrical filters is generally sufficient.
On the other hand, if it is a mechanical filter, it is advisable to rinse the membrane and the filter sponge weekly to keep it in good working order. Once these elements are embedded, it is difficult to reuse them in optimal efficiency conditions.
Cleaning your aquarium filter – More important information
Cleaning the filter is not workmanship that must be done weekly, at each water change, but only when, due to accumulated misery, it can no longer perform its function effectively.
The filter performs 3 types of filtration: mechanical, chemical and biological. By means of the sponge filter elements, they retain a series of particles that are suspended in water, therefore over time, the pores of these filter elements clump and the water can no longer circulate freely through the filter.
As a consequence, the biological and chemical filtration capacity also decreases, causing harmful substances for aquatic life.
Practically, filter media cleaning is done to restore the mechanical filtration function. The decision to clean it is taken once the marked decrease of the return flow is observed.
External filters (canister type) contain a large number of filter elements (they have a large filtering surface) and require less time to clean.
Conversely, small (internal) filters need to be cleaned more often. If a prefilter is attached to the filter path, it is necessary to clean the filter itself because it stops most of the particles from the water and can be easily cleaned weekly, avoiding complete cleaning of the external filter that is very time-consuming.
As the aquarium cycles and after this period, a series of bacteria beneficial to the equilibrium of an aquarium are deposited on the filter materials.
They help eliminate some fish-damaging substances. These bacteria can be easily removed during the thorough cleaning of the filter elements, which is undesirable.
Filter materials do not have to be squeezed.
Filter elements (sponge, polyp, etc.) are extracted from the filter and cleaned in a water tank (preferably water removed from the aquarium). Cleaning is done gently by manually removing visible macroscopic substances.
A sponge squeeze should also be avoided. These materials can also be cleaned under a faint jet of tap water, but with caution, not to remove a large number of bacteria that colonize the filter in this process. The biological filter elements (rings and ceramic cylinders) are rinsed gently in a bowl with aspirated water from the aquarium to remove visible coarse dirt.
With time inside the aquarium hoses, a number of substances are deposited that substantially narrow their diameter, causing a marked decrease in the flow of the filter. They can be cleaned easily using long cleaning wipes.
It is easy to understand that cleaning the filter will not use soaps, detergents and other substances of this nature. Cleaning the filter, as mentioned above, only serves to remove the dirt that mechanically clogs the filter media, so delicate rinsing is sufficient.
Using UV as a method of keeping the water clean
Using UV lamps – Are they better than UV filters? Are they efficient and safe?
UV light sterilizers are used for aquariums to help eliminate algae, parasites, and unwanted bacteria. Light from UV lamps alters and disrupts the cellular structure of harmful algae and bacteria, thereby destroying their reproductive properties.
Eliminating them from the aquarium is made very easy by the UV filter since all the water that reaches the aquarium will pass in one moment or another through it. Most people install the filters so that with the water supply, they will pass directly through the sterilizer. The system has UV lamps that will light as the water passes through it.
It is important that when choosing a sterilizer with UV lamps, choose the right one for the flow rate and the size of the aquarium to which it will be installed, otherwise, the filter will not work properly and the bacteria and choices will not be eliminated.
It is also possible to find an aquarium that has already installed the optimum filter for its size and flow, so manufacturers want to come to help customers.
Installation of sterilizers with UV lamps is more common for marine-based aquariums than for freshwater aquariums. In freshwater aquaria, there are planted different beneficial algae that use all the resources available to them and care to destroy any trace of bacteria, parasites, and algae that could affect the aquarium ecosystem.
You must remember that sterilizers with UV lamps do not differentiate between beneficial and harmful algae so they will destroy any plant that will enter their range.
If you plan to use such a filter and you do not want to kill any of the free-floating planktonic animals such as amphipods or Copepods, then you should buy a filter that you can set to act only when the light is out, considering that these useful lives for your aquarium tend to hide in the day.
Sterilizers with UV lamps can have a negative or neutralizing effect on the treatments you add to aquarium water, so be sure to stop the filter if you treat fish with different chemicals.
The last thing I want to add is that the UV lamps of the sterilizer should be replaced every 6 months, which is a cost that you need to consider when deciding to buy such a product. A UV lamp should never be used more than recommended, this action being very dangerous for both your fish and you.
Finally, I would remind you that for a freshwater aquarium there is no need for a water filter, although it is still recommended to install one.
In the case of marine aquariums, the situation is changing: a UV lamp sterilizer is an accessory that you can not miss if you want to have happy and healthy fish, but you have to be very careful to choose the right filter for your aquarium size, in case otherwise you will do more harm than good.
Why it is Important to Have a Filter in Your Fish Tank
Inevitably both fish and other aquarium organisms eliminate metabolic products in water that can negatively influence the quality of the water, and if these substances are ignored, they can lead to the death of the fish.
Filtering is absolutely mandatory in an aquarium, it provides optimum water for life, clear and clean water, enhanced aquarium illumination which makes it more appealing.
Filtration is the process by which the suspended components are removed from the water, otherwise, the water is cloudy and repellent. Depending on how these particles are removed, there are three types of filtration:
Physical filtering can be done by both internal and external filters. It passes the water through a series of filtering materials, which are still finer that retain the particles in the water like a sieve, then the water resumes its circuit in the aquarium.
The most used filters were the so-called “wobbly filters” but they gradually lost ground to the best. They are made up of a sponge with outer strips and a hollow inside that will insert a loudspeaker with a hose connected to an air pump.
Thus, the air will rise rapidly and create a low pressure inside the sponge to equalize the pressure, the aquarium water will enter the sponge body where the particles will be retained in the water.
After a few days of operation, the sponge is removed from the aquarium, washed until the water passing through it comes out clear and clean and then reintroduced into the aquarium. This type of filter is very simple and has its drawbacks: it is unsightly and does not have a very high yield.
Another example of the filter type is the internal filter, it is a device that works on the same principle but has a higher efficiency because, being electrically driven, it can filter a much larger volume of water than the bulky.
This type of filter is very used and is currently the main filter of personal aquarium owners, being a relatively inexpensive and performance variant for an aquarium up to 150 liters. As in the previous case, and this filter should be washed regularly, otherwise, the pump will not be able to provide an equal flow and the filtering is aggravated.
Other types of mechanical filters can use sand, gravel, cotton, sponge, active carbine or other natural or synthetic porous media as filter media. They can be done quite easily by a person who understands the principle of operation (photo) from a simple aquarium.
This must be done in such a way that the water in the fish aquarium enters the aquarium that will become a filter, pass through a series of filter media and return to the main aquarium.
The flow of water can be done by means of an internal filter head (ie the engine box). This type of filter is very efficient and inexpensive, is easy to maintain because, unlike others, it does not require frequent washing of filter media.
Filtering media must be arranged so that it is finer, starting with gravel and ending with cotton, but there may also be a single filter medium, for example, the only cotton, but it must be compact to make it more efficient filtering.
These filters must be located near the aquariums they will filter and must be masked so as not to disturb them aesthetically. They can be incorporated into the furniture or in the wall, but they must be easily accessible.
Biological filters are those filters that, in addition to retaining particles in the water, provide light and heat, beneficial to the development of algae and bacteria.
These algae colonies will use for their own development the ammonium ions and phosphatic salts, damaging the aquarium.
A biological filter variant is a filter located above the aquarium, made of a PVC gutter inside which are synthetic fibers or sand and which is provided with a multitude of holes that allow the circulation of water. Once past the filter, the water will be released from the suspension components and will fall freely in the aquarium in the form of rain.
Organic matter encounters numerous aerobic bacteria in the filter material that mineralize it. Algae play an important role in providing oxygen through the photosynthesis process and the use of components decomposed by aerobic bacteria such as ammonium ions and phosphate salts for their own food.
Partial water treatment can be done relatively simply with a so-called former. This extremely simple installation is based on an air pump and a loudspeaker. Pressurized air through a tube causes an intense stirring of the water, which causes the formation of highly charged white foam and colloidal substances. This greenish foam is then picked up in a cup and removed.
UV radiation filtration is used in marine aquariums and ponds to reduce greengill turbidity, this radiation is fatal to micro-organisms, and if treated, they are killed and water is practically sterile
But this type of filtration has drawbacks neutralizes important microelements for plants, one of which is iron, but it is recommended to be used after a drug treatment because it decreases or even cancels the action.
How to filter the aquarium must be chosen according to several factors to have a crystal clear water and a healthy aquarium:
- the number and size of the fish;
- the volume of the aquarium;
- fish species and aquarium plants;
- type and amount of fish food;
- The number of fertilizers in the water.
Regardless of the filtering method chosen, it is good for each aquarium to refresh each week by removing 25-30% of the water and adding the same amount of fresh water. These refreshers complete filter failures, ie provide a low concentration of nitrogen compounds (ammonia, nitrates, nitrates) and compounds of other elements that can be fatal to fish in the aquarium.
How often should you clean an aquarium filter? It is recommended that you clean your aquarium filter once every 2 weeks. It is important to keep it in the right shape and condition in order for it to work properly.
Should aquarium filter always be on? Yes, they should always be working. It is important to keep constant water flow into your tank in order to avoid fish diseases and unbalanced water parameters.
Can aquarium filters be turned off at night? They can, but we don’t recommend that. It is important to leave them working at all time.
You can choose from different variants, but most often you will find models that are mounted with suction on the corner of the aquarium.
They pump compressed air to the base of the pool, so the residual particles rise to the surface and you can easily gather them with a net. If you install them correctly and position the pump very close to the surface of the water, the nozzle forms a spring of water and facilitates aeration.
Other models also sprint, with the help of a pump, a subtle water movement that passes through absorbent sponges. Waste is retained inside, but you need to clean or change it regularly.
Some filter cameras are modular so you can introduce different cleaning materials to complement each other. More reviews about the best cheap aquarium filters make you choose one that combines biological and physical filtering.
Always take into account the capacity of the aquarium and the needs of the caretakers you care for. Typically, manufacturers specify the maximum volume of water that the product can handle. Depending on this, the maximum filter flow rate also varies. For example, for a pool of over 120 liters, you will need a 700l / hour flow.
The smaller the aquarium, the lower the flow. Always adjust it, depending on the water volume and the sensitivity of your fish. Do not try to clean faster, at a higher rate, because plants and animals will suffer.
Also, if you recreate small animal or insect living conditions, and the vessel integrates micro-beaches and specific vegetation (as it happens when you decorate terrariums), choose a suitable model for the depth of water in the micro-universe you’ve organized.