Alumina Tubing

If you are planning on building a new home or just remodeling your existing home one of the tougher decisions you may have is choosing the right pipe for your project. Not all piping is created equal, there are several different flavors on the market today that are old, new and true so which is right for you? If you have your own well the first thing you should do is get a water sample and send it in to your state water testing facility. They will test your water for hardness, types of metals that are in your water and the ph or acidity levels. If your acidity levels are high I would definitely recommend staying away from any metal piping such as copper or galvanized. Use any of the following plastic pipes and tubing below. More about active water in a moment. CPVC: This was the first plastic to cut into the copper market, as a matter of fact, my house was originally plumb with cpvc piping. The problem I had with this piping is after 15 years of use and when I finally had to make a repair to the system, it crack three foot down the pipe when I made my cut with ratcheting scissors.

PEX tubing: This is the king of all of the plastics as far as I am concern. I love this stuff. It is also the fastest to install over any other pipes or tubing's on the market today. Although the tools to install this type of tubing is quite costly.

Let's talk a bit about my favorite piping, the old but true metal pipe copper. Besides Galvanized, this is the stuff all of us old timers cut our teeth on and if you have a home that is thirty years or older, more than likely this is the type of water supply you have in your home. Copper commonly comes in roll tubing in boxes of 25 feet to 100 feet per box or rigid sticks of 10' to 20' feet in length. There are three grades of copper pipe: Type K, is the thickest of the three pipes. It has green lettering on pipe and is the most expensive. L piping has blue lettering and M has red lettering. L and M grade copper is the most commonly used in residential plumbing. The common use with type K is in industrial plumbing systems or refrigeration. Low bidders usually use type M copper pipe. Diameter References:

Copper comes in both inside (ID) and outside diameters (OD). Plumbers use ID diameters, while HVAC Installers use OD for the same tubing. The Common ½-in. copper tubing used in residential plumbing is also referred to as 5/8- in. tubing in the HVAC industry.

Repair

For the home owner, repairing any of the above pipes and tubing mention in this article is a snap. Purchase "shark bites" fitting and the u shaped tool to mend or add to any part of your system. Shark bite fittings can be found at your local plumbing shop. They are a little costly, but you will make the cost back in time and ease of use.

In the last few years Copper has been getting a bad name because acidic water or active water will corrode the pipe.

Plus the EPA commission has listed copper as contaminate. It is my understanding that the maximum level of copper, according to EPA standards, is 1.3 parts per million (1.3 mg/L). Copper tubing should not be installed for water piping systems having acidic water conditions with a pH of 8.5 or less. Private wells and mountain communities can have a pH of less than 6.5 This is why I recommend that you test the pH of your water if you plan to use copper or any type of metal piping for your potable water system.

If you are on a community water system, check with your local authorities for recommendations. I also recommend, not to install metal piping without conditioning the water with an acid neutralizer first. Rigid copper needs to be solder. If you are not familiar with the soldering procedure involved in making a leak free joint then I recommend that you call your local plumber to install or repair your plumbing system.

Pipes and Tubing's: Choose Your Flavor Pipes and Tubing's: Choose Your Flavor

If you are planning on building a new home or just remodeling your existing home one of the tougher decisions you may have is choosing the right pipe for your project. Not all piping is created equal, there are several different flavors on the market today that are old, new and true so which is right for you?

If you have your own well the first thing you should do is get a water sample and send it in to your state water testing facility. They will test your water for hardness, types of metals that are in your water and the ph or acidity levels.

If your acidity levels are high I would definitely recommend staying away from any metal piping such as copper or galvanized. Use any of the following plastic pipes and tubing below. More about active water in a moment.

CPVC: This was the first plastic to cut into the copper market, as a matter of fact, my house was originally plumb with cpvc piping. The problem I had with this piping is after 15 years of use and when I finally had to make a repair to the system, it crack three foot down the pipe when I made my cut with ratcheting scissors.

PEX tubing: This is the king of all of the plastics as far as I am concern. I love this stuff. It is also the fastest to install over any other pipes or tubing's on the market today. Although the tools to install this type of tubing is quite costly.

Let's talk a bit about my favorite piping, the old but true metal pipe copper. Besides Galvanized, this is the stuff all of us old timers cut our teeth on and if you have a home that is thirty years or older, more than likely this is the type of water supply you have in your home.

Copper commonly comes in roll tubing in boxes of 25 feet to 100 feet per box or rigid sticks of 10' to 20' feet in length.

There are three grades of copper pipe:

Type K, is the thickest of the three pipes. It has green lettering on pipe and is the most expensive. L piping has blue lettering and M has red lettering. L and M grade copper is the most commonly used in residential plumbing. The common use with type K is in industrial plumbing systems or refrigeration. Low bidders usually use type M copper pipe.

Diameter References:

Copper comes in both inside (ID) and outside diameters (OD). Plumbers use ID diameters, while HVAC Installers use OD for the same tubing. The Common 1/2-in. copper tubing used in residential plumbing is also referred to as 5/8- in. tubing in the HVAC industry.

Repair

For the home owner, repairing any of the above pipes and tubing mention in this article is a snap. Purchase "shark bites" fitting and the u shaped tool to mend or add to any part of your system. Shark bite fittings can be found at your local plumbing shop. They are a little costly, but you will make the cost back in time and ease of use.

In the last few years Copper has been getting a bad name because acidic water or active water will corrode the pipe.

Plus the EPA commission has listed copper as contaminate. It is my understanding that the maximum level of copper, according to EPA standards, is 1.3 parts per million (1.3 mg/L).

Copper tubing should not be installed for water piping systems having acidic water conditions with a pH of 8.5 or less. Private wells and mountain communities can have a pH of less than 6.5 This is why I recommend that you test the pH of your water if you plan to use copper or any type of metal piping for your potable water system.

If you are on a community water system, check with your local authorities for recommendations.

I also recommend, not to install metal piping without conditioning the water with an acid neutralizer first.

Rigid copper needs to be solder. If you are not familiar with the soldering procedure involved in making a leak free joint then I recommend that you call your local plumber to install or repair your plumbing system.

If you are planning on building a new home or just remodeling your existing home one of the tougher decisions you may have is choosing the right pipe for your project. Not all piping is created equal, there are several different flavors on the market today that are old, new and true so which is right for you?

If you have your own well the first thing you should do is get a water sample and send it in to your state water testing facility. They will test your water for hardness, types of metals that are in your water and the ph or acidity levels.

If your acidity levels are high I would definitely recommend staying away from any metal piping such as copper or galvanized. Use any of the following plastic pipes and tubing below. More about active water in a moment.

CPVC: This was the first plastic to cut into the copper market, as a matter of fact, my house was originally plumb with cpvc piping. The problem I had with this piping is after 15 years of use and when I finally had to make a repair to the system, it crack three foot down the pipe when I made my cut with ratcheting scissors.

PEX tubing: This is the king of all of the plastics as far as I am concern. I love this stuff. It is also the fastest to install over any other pipes or tubing's on the market today. Although the tools to install this type of tubing is quite costly.

Let's talk a bit about my favorite piping, the old but true metal pipe copper. Besides Galvanized, this is the stuff all of us old timers cut our teeth on and if you have a home that is thirty years or older, more than likely this is the type of water supply you have in your home.

Copper commonly comes in roll tubing in boxes of 25 feet to 100 feet per box or rigid sticks of 10' to 20' feet in length.

There are three grades of copper pipe:

Type K, is the thickest of the three pipes. It has green lettering on pipe and is the most expensive. L piping has blue lettering and M has red lettering. L and M grade copper is the most commonly used in residential plumbing. The common use with type K is in industrial plumbing systems or refrigeration. Low bidders usually use type M copper pipe.

Diameter References:

Copper comes in both inside (ID) and outside diameters (OD). Plumbers use ID diameters, while HVAC Installers use OD for the same tubing. The Common 1/2-in. copper tubing used in residential plumbing is also referred to as 5/8- in. tubing in the HVAC industry.

Repair

For the home owner, repairing any of the above pipes and tubing mention in this article is a snap. Purchase "shark bites" fitting and the u shaped tool to mend or add to any part of your system. Shark bite fittings can be found at your local plumbing shop. They are a little costly, but you will make the cost back in time and ease of use.

In the last few years Copper has been getting a bad name because acidic water or active water will corrode the pipe.

Plus the EPA commission has listed copper as contaminate. It is my understanding that the maximum level of copper, according to EPA standards, is 1.3 parts per million (1.3 mg/L).

Copper tubing should not be installed for water piping systems having acidic water conditions with a pH of 8.5 or less. Private wells and mountain communities can have a pH of less than 6.5 This is why I recommend that you test the pH of your water if you plan to use copper or any type of metal piping for your potable water system.

If you are on a community water system, check with your local authorities for recommendations.

I also recommend, not to install metal piping without conditioning the water with an acid neutralizer first.

Rigid copper needs to be solder. If you are not familiar with the soldering procedure involved in making a leak free joint then I recommend that you call your local plumber to install or repair your plumbing system.

Type K, is the thickest of the three pipes. It has green lettering on pipe and is the most expensive. L piping has blue lettering and M has red lettering. L and M grade copper is the most commonly used in residential plumbing. The common use with type K is in industrial plumbing systems or refrigeration. Low bidders usually use type M copper pipe.

Diameter References:

Copper comes in both inside (ID) and outside diameters (OD). Plumbers use ID diameters, while HVAC Installers use OD for the same tubing. The Common 1/2-in. copper tubing used in residential plumbing is also referred to as 5/8- in. tubing in the HVAC industry.

Repair

For the home owner, repairing any of the above pipes and tubing mention in this article is a snap. Purchase "shark bites" fitting and the u shaped tool to mend or add to any part of your system. Shark bite fittings can be found at your local plumbing shop. They are a little costly, but you will make the cost back in time and ease of use.

In the last few years Copper has been getting a bad name because acidic water or active water will corrode the pipe. Plus the EPA commission has listed copper as contaminate. It is my understanding that the maximum level of copper, according to EPA standards, is 1.3 parts per million (1.3 mg/L).

Copper tubing should not be installed for water piping systems having acidic water conditions with a pH of 8.5 or less. Private wells and mountain communities can have a pH of less than 6.5 This is why I recommend that you test the pH of your water if you plan to use copper or any type of metal piping for your potable water system.

If you are on a community water system, check with your local authorities for recommendations. I also recommend, not to install metal piping without conditioning the water with an acid neutralizer first.

Rigid copper needs to be solder. If you are not familiar with the soldering procedure involved in making a leak free joint then I recommend that you call your local plumber to install or repair your plumbing system.

William Cato, has been working in the Plumbing industry since 1984 and has been a professional plumber for the last seventeen years. He specializes in Repair and remodel plumbing. William is currently working for a contractor from Denver North Carolina.

Alumina Tube

Since the mid-1960s much development work has been undertaken on rechargeable batteries using sodium (Na) for the negative electrodes. Sodium is attractive because of its high reduction potential of -2.71 volts, its low weight, its non-toxic nature, its relative abundance and ready availability and its low cost. In order to construct practical batteries, the sodium must be used in liquid form. Since the melting point of sodium is 98 °C (208 °F) this means that sodium based batteries must operate at high temperatures, typically in excess of 270 °C (518 °F).^{[citation needed]}

Sodium-sulfur battery and lithium sulfur battery comprise two of the more advanced systems of the molten salt batteries. The NaS battery has reached a more advanced developmental stage than its lithium counterpart; it is more attractive since it employs cheap and abundant electrode materials. Thus the first commercial battery produced was the sodium-sulfur battery which used liquid sulfur for the positive electrode and aceramic tube of beta-alumina solid electrolyte (BASE) for the electrolyte. Corrosion of the insulators was found to be a problem in the harsh chemical environment as they gradually became conductive and the self-discharge rate increased. A further problem of dendritic-sodium growth in Na/S batteries led to the development of the ZEBRA battery.

Alumina Silicate

There are many reasons for thermal shock failure in industrial applications of ceramics. On analysis they usually come down to one or more of the following factors.

• Material selection
• Material processing
• Design of component

Application/use of the product

It is often possible to improve the performance by changing one or more of these but as with all ceramic applications thermal shock is only part of the equation and changes must be looked at in context of all the performance requirements.

When designing any product in ceramic it is necessary to look at the overall requirement and often then to find the best compromise that will work.

In high temperature applications, thermal shock is often the main cause of failure. It is comprised of a combination of thermal expansion, thermal conductivity and strength. Rapid changes in temperature both up and down cause temperature differentials within the part, not unlike a crack occurring by putting an ice cube against a hot glass. Movement through differing expansion/contraction leads to cracking and failure.

There are no simple answers to the thermal shock issue however the following guidelines do tend to be beneficial.

• Select a material grade that has some inherent thermal shock characteristics but meets the needs of the application. Silicon carbides and silicates are excellent. Alumina based products are less good but can be improved with the right design.
• Porous products are generally better than impervious and will take larger changes in temperature.
• Thin walled products perform better than thick wall. Also avoid large transitions in thickness throughout the part. Sectional parts may be better as this provides less mass and offers a Pre cracked design alleviating stress raisers.
• Minimise the use of sharp corners as these provide ideal starting points for cracks.
• Avoid tension loading of the ceramic. Parts can be pre stressed through design to help alleviate this problem.
• Where possible look at the application process to see if it is possible to provide a more gentle change in temperature. Pre heating the ceramic or reducing the rate of temperature change.

The above points will help alleviate thermal shock problems but it is always best to discuss the situation with experts in the field.

Alumina Rod

Abrasive is a very hard material, commonly used for grinding, polishing, sharpening, cutting, buffing, drilling, and honing the surfaces, they can be differentiated into synthetic or natural. Many a synthetic abrasive is productively equivalent to an organic mineral. It differs only in the fact that synthetic minerals are manufactured instead of mined. If natural minerals are impure, they tend to be less valuable. Nowadays, they are synthetic. Some of the abrasive minerals (zirconia alumina) appear naturally though sufficiently more intricate and expensive to acquire , because of this, synthetic stones are made use of industrially. These are also called artificial abrasives. Other forms of artificial abrasives comprise ceramics, silicon carbide (carborundum), zirconia alumina, alumina or aluminum oxide.

Abrasives structured for individual purposes. Most of the organic abrasives are minerals, Generally synthetic and natural come in a gamut of shapes, commonly known as coated or bonded abrasives, including wheels, belts blocks, discs, rods, sheets & loose grains. Manufactured abrasives are classified into two types coated, and bonded abrasives. Bonded is one of the abrasive materials that are hold within matrix, and aluminum oxide.

Abrasives contain sintered material. This type of matrix is known as a binder also called as clay, rubber or resin. This combination of binder & the abrasives are normally structured as wheels, sticks, blocks. These are commonly used as aluminum oxide, silicon carbide, garnet, tungsten carbide.

Bonded abrasives are required to be dressed after they are used. Dressing includes various processed including cleaning the waste material from the surface and revealing the new grit. It depends upon the abrasive and how it is used.

Coated abrasives are also minerals that are used in the same way as bonded abrasives. Sandpaper is a best example of coated abrasive. Coated abrasives are structured for use in orbital sanders.

To know more about Abrasives, please read our useful section on the types of abrasives in detail.

Mr. Shameer Khan has done intensive research on Electro minerals & Abrasives and chats regularly in various Technical Discussions & forums including Ceramics, Power Tools & Super Refractories.

Alumina Properties

A metallic element with symbol Al, aluminum is the 3rd most plentiful element of Earth's crust, behind that of oxygen and silicon. The metal has strong affinity towards oxygen and hence is not found in the elemental form but in combined states, such as silicates or oxides.

Bauxite is the main mineral ore of aluminum, which is abundantly available in tropical areas, such as - Africa, the West Indies, South America and Australia. Bauxite contains all types of impurities - mainly metals, such as iron - but comprises of 45 % to 60 % aluminum oxide, or alumina.

In its metallic form, aluminum metal does not occur naturally. It occurs only in combination with other minerals in the form of oxide or silicate compounds that constitute about 8% of earth's crust.

According to estimates, about 29 million tons of aluminum is required to meet the global demand every year. Of this total 29 million tons of total aluminum, around 22 million tons is new aluminum and 7 million tons is obtained by recycling the aluminum scrap. About 25% of the total amount of aluminum used across the world is recycled material.

Fact - 50% of the aluminum cans used today in the US are recycled.

According to estimates since 1972 around 16 million tons of aluminum cans have been recycled. These 785.6 billion aluminum cans if placed end-to-end could stretch to the moon more than 249 times.

Production of Aluminum

Production of aluminum is a two stage process that comprises of various intermediate steps. In the first stage, different mechanical and chemical stages are used to purify the bauxite and recover the alumina with the help of "Bayer Process".

Once the alumina - aluminum oxide trihydrate - is retrieved, it can be electrolytically reduced (transformed through electrochemical means) into metallic aluminum.

Some Facts -

• Aluminum can be very strong, light (less than 1/3rd of the specific gravity of copper, brass or steel), ductile, and malleable.
• The metal is an excellent conductor of heat and electricity.
• Polished aluminum has the highest reflectivity of any material - even mirror glass.
• The metal can be rolled, cast or extruded into an infinite array of shapes.
• As a packaging material, aluminum as unique barrier characteristics. It resists corrosion and can be recycled again and again, without any loss of quality or properties.
• The metal can be mixed with small, often minute, quantities of other materials, such as - copper, zinc, silicon, iron, magnesium, tin, titanium, lithium, chromium, tungsten, manganese, nickel, and others to create a variety of alloys with very different physical characteristics.
• Aluminum metal is so widely used in todays' modern world that it is very difficult to imaging a world without it. The amazing, unique properties of this fundamental metal give it an extensive array of possible applications, including - transport, packaging, electrical application, medicine, and construction of homes and furniture.

Alumina Oxide

Today, anodizing wear resistant coatings for aluminum surfaces can be made harder than tool steel. How? Through modifications of anodize, a process common in the finishing industry for electrolytic treatment of metals to form stable films or coatings on the metal surface. Anodized aluminum or magnesium, for example, are typically associated with functional coatings like hard anodize, also known as 'hardcoat'.

And they can be made so much more.

In the anodic coating process, unlike electroplating, the work is made the anode, and its surface is converted to a form of its oxide that is integral with the metal substrate.

Generally, it's agreed that the ceramic oxide coating consists of two layers:

The initial layer, which forms right at the surface, is called the barrier layer. It is a comparatively thin, dense, and nonporous form of aluminum oxide.

Next form the outer, heavier layers of the anodic coating. They are more porous and are stacked somewhat like parallel tubes extending through the layer, from the outermost surface down nearly to the barrier layer.

It's important to recognize that, unlike plating, whose thickness accumulates by depositing more and more onto the outermost surface, the anodic layers form by oxygen transfer from the underlying aluminum surface and force existing layers outward.

This means that oxides newest forming are always located between the metal surface and the last, most recently formed alumina oxide. Consequently, the greater the thickness, the lower the density of coating at the outermost surfaces, based on longer solvent action of the electrolyte. Consequently, for maximum wear resistance, more is not always better.

A factor to consider in your design, such as close tolerance bores, bearing diameters, dowel holes or threads, is that the resultant growth portion of the coating is a fractional percentage of the total coating thickness. Hard anodize, for example, will typically result in 50% penetration and 50% buildup.

Keep in mind that buildup is normal or perpendicular to the surface and sharp corners should be rounded to avoid chipping.

To anodize aluminum, one of the most important factors influencing oxide formation is composition of alloy. Reaction of all the various possible alloying or impurity constituents can result in coating voids or disruptions, while other constituents may themselves oxidize in the conditions of anodizing and lessen the intended properties.

Depending on electrolyte, a wide range of thickness can be obtained. Coatings produced in sulfuric acid electrolyte, for example, can be as low as 0.0001 inch (2.5 um) to as high as 0.003 inch (75 um).

Anodic coatings have a definite cellular structure. Imagine individual cells with pores down their centers totaling millions per square inch. This makes for excellent dyeing and sealing. Sealing processes make the coatings non-absorptive and include, immersion in boiling de-ionized water, steam, or nickel acetate.

De-ionized water is often preferred as a sealing solution for its ability to react with anhydrous aluminum in the outer layers of the film. A mono-hydrate of the oxide is formed, which occupies greater volume than the alumina from which it was formed. The result is a reaction to close down and plug the pore structure.

Structures of hard anodizing can be supplemented with a variety of materials, including Teflon (PTFE) waxes, oils and other compounds, to lower friction or add release. And because these compounds penetrate the ceramic with negligible surface growth, making their wear resistance simply exceptional.

So, next time, reduce the weight in your design. Instead of steel, think hard anodizing wear resistant coatings for aluminum.

Want more information? Need help with your surface engineering? We care! Just visit us at:

Anodizing

William Gunnar, a degreed scientist, researcher, engineer, and friend, has helped thousands of 'best of class' product designers and equipment manufacturers -- for nearly 20 years now -- surface engineer with coatings for success.

His publication, Industrial Coatings World, brings wisdom, honesty, leading edge information, and no nonsense advice to thousands weekly. Put together by some of the world's leading experts in coatings and manufacturing, his FREE newsletters are truly must-reads for those who want to be 'in-the-know'.

Alumina Crucibles

When the novice hobby metal caster first thinks about melting metal, the immediate thought is to collect a big box of Al bottle tops and Al drink cans to melt. The most likely reason for this is that the material is relatively easy to collect and handle, and the thinking behind the idea is that because of its lightweight it should melt quite readily.

Then why is it so difficult to melt & reclaim aluminium drink cans, bottle tops & swarf in a hobby gas fired crucible furnace?

To melt & reclaim light weight scrap aluminium requires the use of some specialised equipment. Most commercial scrap metal
recovery foundries use what is known as a rotary type melting
furnace. This type of furnace is designed in such a way that
the flame actually strikes the rotating furnace lining, and the
heat spreads quickly around the furnace walls, which absorb
the heat. As the furnace rotates, the heat is also taken up or
absorbed by the scrap metal.

It is essential to melt the metal under a cover of MOLTEN FLUX, otherwise very heavy metal oxidation results and subsequently
very little metal is actually recovered.

As each piece of small swarf or chip melts, it forms a globule of
liquid metal surrounded by a shell of oxide. The skin tension of
this oxidant around the globule prevents coalescence, i.e. (to grow together) and because of the large surface area presented
by the mass of globules, with the increase of oxide formation loss of yield is bound to take place.

The skin of the oxide on the molten globule has to be "ruptured" in order to allow coalescence, i.e. to allow the clusters of globules to actually join together in their molten state.

A molten flux encourages coalescence by chemical action.

While the rotation of the furnace provides a mechanical action.
The special fluxes; coveral 48 & 57 provide the chemical action,
they are the best type of fluxes to use when melting Al metal in
the region of 590 to 600 C. (Coveral 48 & 57 products are copyright Foseco Pty Ltd)

This flux may or may not provide similar results when used in a normal crucible gas fired furnace, but the yield loss will still be considerable.

The hobby foundry worker would be better off directing his
energy towards collecting easier to source, better quality scrap
to melt, such as discarded cylinder heads, inlet manifold castings, auto pistons, etc. Or if the budget stretches that far, purchase commercially produced ingots, which are of a known quality. Commercial ingots will provide top quality metal right from the word go.

Trying to melt lightweight Al drink cans and bottle tops is generally a waste of time for the hobby worker, unless you use the fluxes mentioned above, and use the correct furnace. Otherwise a lot of gas will be wasted heating the hobby crucible furnace for very little gain in metal yield.

Alumina

There are a couple of ways you can remove fluoride from your water at home. One of these is with a reverse osmosis water filter. These are usually installed under your kitchen sink and they work by forcing water through a membrane that blocks fluoride from passing through so the water that is collected on the other side is free from fluoride and many other contaminants.

The second way to remove fluoride from your drinking water is by using an activated alumina cartridge. This type of fluoride water filter is smaller and sits on your counter top. It is also much less expensive than a reverse osmosis water filter.

Why would you want to remove fluoride from your drinking water? If you have children, they can develop dental fluorosis if they consume too much fluoride while their teeth are developing. Children are at risk for this condition up until they are eight years old. Most children with fluorosis have mild cases which appear as white spots and lines on the teeth that are not too noticeable. Severe cases are less common but these cases can have symptoms of pitted and cracked teeth that are stained brown or black.

Fluoride is also linked to a number of other ailments such as increased risk of cancer and possibly even Alzheimer's disease. Fluoride is actually a pollutant, being created as a by product of iron, copper and aluminum manufacturing. It has even been used as a rat poison and insecticide. Many think there is no clear link between fluoride and decreased dental cavities.

Whether you want to consume water with fluoride is a personal decision. But since most municipal water supplies in the United States have fluoride added, if you want to drink water without it, you will have to use a fluoride filter to get it out.

Boiling water will not remove fluoride, it only concentrates it. Fluoride cannot be removed through distillation either. You should know that bottled water may also have fluoride unless it states on the label it has been filtered using reverse osmosis.

Price may be a deciding factor when trying to choose between the two types of fluoride filters. Reverse osmosis water filters are much more expensive than activated alumina cartridges. Expect to spend a few hundred dollars for a reverse osmosis system while you can pick up an alumina cartridge for well under $100.

Consider also if you need other contaminants removed from your water. A high quality reverse osmosis system can remove chlorine and E-coli along with many other impurities. Become aware of all of your choices before selecting your water filtration system. Water filters have their advantages and disadvantages, which you choose depends a lot upon the source of your drinking water.