The Difference Between Granular Activated Carbon and Activated Carbon Block Water Filters
Activated carbon filters are frequently used as a complimentary filter for UV and reverse osmosis water filters. When it comes to choosing an activated carbon filter for these type of systems, you generally have two choices: granular activated carbon (GAC) or carbon block. Although both GAC and carbon block filters are both made from carbon that has been ground into small particulate matter, this is basically where the similarities end.
Granular Activated Carbon in loose form vs a Solid Carbon Block
Carbon block filters have a much larger surface area, which allows them to filter out a much larger quantity of water while also being much more affective at filtering out particles, heavy metals and other contaminants. Now this isn’t to say that granular activated carbon filters are necessarily a bad choice, but it does mean that you need to be fully aware of the differences between these two types of filters in order to make a more informed decision. For this reason, we will now present a quick overview of both granular activated carbon and carbon block filters to make it easier for you to decide which is a better fit for your needs.
Granular Activated Carbon vs Activated Carbon Block Filters
Granular activated carbon filters are made using carbon that has been ground up and is held together loosely inside a cartridge or other container. On the other hand, carbon block filters are made by grinding activated carbon into a fine powder. This powder is then mixed with a food-grade binder, and the resulting mixture is then heated up and compressed into a solid block. Although both types of filters use ground carbon, the carbon found in block filters is usually ground into a much finer powder. In fact, the carbon particles in a block filter are usually 5 to 20 times smaller than the particles used in GAC filters.
The fact that carbon block filters are much more tightly packed than GAC filters means that the blocks filter out far more contaminants. Whereas some contaminants may be able to escape the loose carbon found in GAC filters, the compact nature of carbon block filters means that even the smallest particles and contaminants cannot pass through the filter. In addition, the compact nature of carbon block filters means that it takes water much longer to pass through the filter. This lower flowrate further increases the effectiveness of carbon block filters and contributes to much higher purification rates than when using a GAC filter.
The tradeoff for this level of purification is the low flow rate. The looser nature of GAC filters means that they provide a much higher flowrate, which essentially means that you can purify much more water in less time albeit less effectively. However, some GAC filters are able to achieve higher purification rates by slowing down the flowrate and thus increasing the amount of time that the water is in contact with the carbon. Although they may not provide the same level of purification as carbon block filters, granular activated carbon filters do have the advantage of lasting much longer.
Many water purification systems actually take advantage of both carbon block and GAC filters in different stages of the purification process. This shows that granular activated carbon filters do have their own uses, even if they don’t provide the same level of purification as the carbon block filters. Nonetheless, if you are forced to choose between the two, it comes down to what is most important to you: a higher flowrate or better purification.
Good morning , what is strength the GAC and block carbon against PH ? how are Calculate flow rate and saturation rate?
Hello Ahmed,
The carbon blocks don’t have any significant effect on pH. Flow rate can be measured in the simplest form by just passing water through the block using a housing at constant pressure and recording the total volume of water that passes through it and the time it takes. When a carbon block is saturated it usually chokes, or the flow is drastically reduced.
Hi there, Jin from Australia, can you make custom shape activated charcoal block in different shape ? Regards
Hello Jin, We make custom filters in all shapes and sizes. Please email us your requirements at info(at)rajahfiltertechnics.com
Hi,
I just install a 2 level filtration system, with a sediment as the 1st and activated carbon as the 2nd level. All filter cartridges are come with the housing kits I bought, so I guess the carbon filter is a granulate activated carbon filter. To my surprise, the taste of the water is weird, something like carbon or muddy taste. I have already flush it for long time and have been using it for 2 days, but the taste is still there. Can you tell me if this is normal and what is the cause please? I used to use filter jug which using granulate carbon I believe. Then recently I installed a boiling tap which comes with a filter cartridge (I guess it is a block activated carbon filter), I never taste water like this before. Is it because of the poor quality of the carton filter cartridge came with the kit? I like to find out the reason before I set of to buy a new cartridge as I might water money but not solving the problem if I do not tackle the right issue.
Many thanks
Gavin
Gavin, it’s difficult to answer this without looking at the characteristics of the water. But generally speaking, carbon filters are supposed to remove taste and odor.
Hi,
I wonder if you can documents the purification of water coming out from GAC and Solid carbon filter. Both are activated carbon. Water lab test results will speak for it, which one is better off for home or residential usage. Thank you.
Can Activated carbon be used for greywater filtration? Which is the better for this GAC or BLOCK? also, how long before maintenance as a high volume of greywater will be passed thru it more than 300 L/day.
what kind of filter good for boosting ph?
thank you
hello there,
I have water at PH ranging from 8.4-8.9 before my system, Sainlinty ranging between 250-280, and TDS of almost 350-400 PPM.
I use MRS Everpure ( contains GAC carbon, RO, and post filtration of Hardness cartridge. they called it coffee cartridge.
I have to reduce the PH to below 7.5 and it is quiet difficult for me to do so, as I got PH reading around 8.1 , at TDS of 140-145 and Sainlinty of 90-95. I need to fix it ASAP.
can a carbon block filter made for water used WITH a sub micron particulate filter be used to remove odor and taste from oxygen for breathing?
When installed upstream from a sub micron particulate filter would an inline carbon block filter made for water be effective at removing odor and taste from oxygen for breathing?
I do realize this is not a recommended application for your filters.
I want to built my own system in this order
Sediment filter 20 micron, GAC, sediment filter 10 micron, sediment filter 5 micron, Carbon block then UV 1000ltrs per hour
This is the line up. Is there duplication or alot of redundant components?
Why carbon block able to filter chloromanine but GAC unable to filter it out…althought both using the same carbon material? May you help me to clear this doubt…
Hi. I have a 4 stage filter PP 5 micron, carbon block, carbon block, carbon post filter.
I need to change the filters and my thoughts is that there is no need to put 2 carbon block and replace the 2nd filter with GAC and leave the 3rd as carbon block.
Also I am thinking to change the first filter with PP 1 micron and changing it twice per year instead of once.