Welcome to the beautiful world of aquascaping! In this tutorial today, we’re gonna speak about the most important aspect of the technology behind the aquariums. This is filtration. Just a quick word of warning: I’m gonna present you a lot of theory today, I’m gonna talk about some filters, that we’re using here at Green Aqua. That in no way means that what you’re using, would not be good. Another full disclosure here: This channel is sponsored by Oase. But we’re gonna present you a lot of other brands, that we’re using here at Green Aqua and we’re equally satisfied with. I can say that! Alright, so… [snap] Filtration is important, because you have a lot of decaying organic material in your tank. Decaying organic material will produce Ammonia. Bacteria actually, will produce Ammonia. If you have Ammonia in your tank, that is very toxic to fish and can cause algae. So the main role of a filter is to get rid of that Ammonia and to transform it into Nitrates. Plants are using Nitrates as a nutrient, and they can uptake the Nitrates during the process of their photosynthesis etc., etc. You really need to understand that, in order to be able to keep a healthy aquarium and to have your fish not dying, basically. What is getting rid of Ammonia in your filter? Bacteria. So the first type of filter bacteria will transform Ammonia into Nitrites (NO2). At the second step, the other type of filter bacteria will transform Nitrites (NO2) into Nitrates (NO3). So in contrary, to what many beginner aquarium hobbyists think, filtration is not about “cleaning the water”. It’s about getting rid of the Ammonia from your water. So, this is it! This is the nitrification process. How should a filter look like from the inside? The Green Aqua approach to filtration is: just have three types of filter material in your filter. When the water gets into your filter, It should be filtered through a coarse filter pad. To stop all the floating particles, from entering the filter itself. The sponge is useful for that, As the second step, for the most of the aquarium filter volume you will need a biological filter media. That is a filter media that has a lot of surface area. That’s where the bacteria are living, The bigger surface, the better. Those are gonna decompose Ammonia into Nitrates. As the third step, we have a fine filter mesh, to catch all the floating particles from the water, that was not caught by the coarse filter pad. What else are we using in our filters? We use one more very important thing and that is Seachem Purigen. The Purigen will clean your water removing all tint from it. By our humble and very subjective opinion, after looking at these microscopic images, the best filter media on the market would be the Seachem Matrix. You can see the picture, it’s a very rugged surface. Obviously, it will not change the pH of the water, which is very-very important. The second filter media that we really like is the ADA Bio Rio. This also a very high quality filter media. The problem with it is that the particles themselves are really small, so if you don’t have an ADA filter with a strong pump, your filter can get clogged quite easily. The third filter media that we also highly recommend is the Eheim Substrate Pro. The fourth media that we tested here is the Sera Siporax, which is a medium-kind-of-level filter media. The last picture will show you how the sponge looks under a microscope. you don’t even see two threads of sponge on the picture, it’s so… inefficient. Let’s move on! What kind of other filter things do we have here? We have the ADA NA Carbon here, which is like a Carbon thing. It will also remove Ammonia much quicker and some aquarium hobbyists are using that, at the beginning of the aquarium’s lifecycle. I forgot to tell you that professional filtration, filter media will not remove plant nutrients from your water. So don’t be afraid of that! There are two more products that I wanna show you! The first one is the bacteria colony, that lives in a dormant state in the Seachem Stability. You can use that when cycling a new tank and the Seachem Stability will add the bacteria to your substrate, to your aquarium water and to your filter. The second product that I want to introduce you is the Seachem Prime. That will remove Chlorine from your tap water. So for those of you who are not using an RO – a Reverse Osmosis unit to change the water. Prime is really good… Or similar products, that will remove Chlorine from the water. I think this was too much theory for one day! Let me recap this. I’m gonna put it really simple. You need to buy an external filter. You need to put in the coarse filter pad, which will probably come with your filter, you will not have to change that, at the bottom of the filter, as the first step of the filtration. You will need some biological filter media. If you can get Seachem Matrix, just get it. Fill your filter fully with Seachem Matrix, getting rid of everything that is coming with your filter. And that’s the last step: you should use the fine filter mesh. And you should use the Purigen. That’s it! Filtration – simple. Alright, so let’s talk about the different filter types! The first type of filter that you will see, when you start this hobby, will be the internal filter. I’m having the Oase internal filter here in my hands. It has sponge in it. So no surface at all! You’re supposed to change them to some biological filter media. So just buy 500ml, half-a-liter of Seachem Matrix, pour them in and you’re gonna be fine. I really think that internal filters are only good for aquariums of around 20 to 30 liters, maximum. External filter are much better, because the canister volume is much bigger. You can have a lot of filter media in it! My recommendation is to buy the best quality, that you can and the biggest filter, that you can, for your tank. If you open the top, the taps here, both in unlock position, you can take out the pre-filtration chamber. This is a very good idea from Oase. You have all the sponges in here. Which you can clean, without taking the filter out, to the bathroom, etc. Hose adapter, this is called the hose adapter. This is where the hoses are coming from the aquarium and going back to the aquarium. You’re supposed to keep these filters underneath the aquarium, so never put them right next to the aquarium, on the aquarium cabinet! Because they need some level difference between them, to work. You can remove the filter adapter, just by pressing this to unlock position and then you can just remove it. Take the filter out and clean it. When you have like a five-fold turnover and you have a canister big enough and everything is okay with the filtration, you will probably need to clean it every month. Every two months, or so. What I almost forgot: Never clean your filter media in tap water! So, when you’re taking out this one, just get a bucket of aquarium water, and rinse the filter media in that. Why? Because tap water has a lot of Chlorine. The last type of filtration that I wanna talk about, is the sump filters. Sump filters are good for aquariums above 1000 liters. We have one in the gallery, it’s this tank, on the right side of the picture. And we made a video abut that as well. You can check out the link above! There’s one more small thing, which is remotely connected to filtration and this is the surface skimmer, the Eheim Skim 350. This will clean your water surface. Cleaning the water surface is really good for optical purposes as well, but also for gas exchange purposes. All filters should be going 24 hours per day, they should never ever stop. Why? Because you have bacteria living in them. And bacteria needs Oxygen, to live. Okay, I’m gonna get a little bit technical now. I’m gonna open the Oase BioMaster filter. This is the filter head. The filter head has the heater in it and has the pre-filter chamber in it. Okay, this is where the pump is. This is the filter canister. The filter canister is filled with different types of filter media. I would replace this for example, with fine filter mesh. Usually, the external filters have the first layer of filtration at the bottom. What is this, Oase? You don’t need this! Out with that! You don’t need this either. Actually I forgot to tell you, that if you’re buying an Oase filter from Green Aqua, you will get the Seachem Matrix for free. That’s it! Filter selection! What do I recommend for aquariums, for nano aquariums. The smallest aquarium filter that I would recommend is the Classic-series Eheim. A better choice would be for you to buy the 2422 Experience filter, which is underneath. This filter is already much-much quieter. It already has filter media in it. Another problem with the classic filters is that you need to clean them and they don’t have any taps, usually coming with them. The only exception for that is the 2213050 filter. This is a mid-size Classic filter, that comes with double taps and also, filter media in it. Never ever use the factory recommendations for external filters. I know that they’re gonna always say that some filters are good aquariums. This small, 2211 filter is good for aquariums up to 150 liters. What? The next size would be the 60. This is the 60 liter. This is the 80 liter. The difference between is that this one is higher. For this, I would probably recommend the Oase BioMaster 350. Can we have a bigger one? Guess what? 600 – below this tank. So we actually have the biggest Oase BioMaster filter that there is – currently – below a 60 liter tank. You can never “over-filter” any aquarium. We are here, underneath Filipe’s tank and I’m not gonna show it to you, I’ll just cut it here. You can only see half of it. This is a 120l tank. We are using the biggest, Professional (3-series) Eheim underneath it, that comes with the heater. You can see that temperature is blinking on the top of it. And for anything above this size, I would recommend having multiple filters underneath. Flow. Why is flow important? Flow is important, because – 1) You need to bring the CO2 gas, if you have CO2 injection close to the plants, in every corner of the tank. Secondly, you need to keep all the debris that floats, so that the filter can suck it out. How should you decide which filter to choose? When you’re thinking of flow, you should use a number of 5, a multiplier in calculating the size. So for example if you have a 60 liter tank, the ideal flow rate would be 60, multiplied by 5. That is 300. [NOT 350 😀 ] So you should have a filter, an external filter, that has at least 300 liters per hour strength. For a nano tank you obviously need a higher flow rate. So, like 20, or even 20+ flow rate would be nice. For a big aquarium, you don’t need a five-fold ratio, you would probably need a three-fold ratio. The bigger the aquarium, the smaller the flow rate should be. Ideal is 5. That’s all you need to know about flow. Another question that we regularly get: Why do you need glass in- and outflows? No, you don’t need them. It’s just aesthetics. It’s for design reasons. We should place both filter in- and outflows on the same side of the tank. Plus, if you have two filters in the tank, you can put them both on the opposite side and then you can have a circulation like this. Alright, that’s it, I’m not gonna blah blah some more. Thanks for watching! Please subscribe if you didn’t do so yet! Hit the like button if you like this video, and comment, post any questions you want! Hit the bell button to get notified of our future uploads! Until next week! Bye!


  1. Can someone let me know how mush is the Eheim Nano 6 and 9 gallons price in USA in American Money Dollars around im looking for those nanos very hard to find it in USA… thank you … or any country… but I want Eheim please thank you…

  2. Hi Green Aqua, i love your video. Can i just ask you if i have 90x40x40 tank, its 144L.. Which Canister filter should i choose better? The 760L/H or the 1500L/H one?
    And you said to put filter input and output always on one side, so if i have skimmer and co2 diffuser, where should i put them all together ?
    I really appreciate if you wanna teach me and thank you very much before.. Take care sir..

  3. what is the ultimate way to have crystal clear water …. using RO water and have Purigen and ada bio rio in canister but still a little cloudy

  4. Have a fluvial 207 how can I connect a 1/2 clear hose to filter ? I'm using a glass skimmer that uses 1/2 id hose .

  5. How much Seachem Matrix is needed to replace the blue foam in the Biomaster 350? Is the 100 ml Purigen bag enough?

  6. Really nice and helpful video!! 👍I have a lot of ADA BIO RIO here. Do you think that the Oase Biomaster 350 will work completely filled with BIO RIO? I affraid that it will clog 🤔

  7. Love watching videos from you guys, very educational, would you guys consider making an in-depth video in aquarium lights please?

  8. Hi Balazs,
    first of all, you're making great videos. Great tanks and content!

    I have a 200x57x70 cm tank with an external filtration tank underneath it. I can load the filtertank with up to 12 sponges. The pump makse apr. 1200 L/h. For the flow in the tank i have a Tunze 6105 (3000 – 13000 L/h) running. Low CO2 and low light.

    I was told that to much filter media would be bad for the nutrients. So I reduced the filter sponges to 3 to increase the flow in each sponge. But you said, that it's not possible to overfilter. So what's the way to go for?

    Greetings from Germany.

  9. Hello Green Aqua, could you make a video guide about water quality for planted tank ? all thing about water like PH,GH,TDS,O2,Co2 ….

  10. Hello . What would you suggest for 60P(with chiller) tank (biomaster250,350 or eheim classic600) ? , I like Oase model it modern.Biomaster filled with eheim substrat pro .

  11. Hi , love your work great video and good explanation. I have a 220L planted aquarium with no drift wood and the water always goes yellow every time I change water is will clear for couples of days then is turn yellow again. Is this my filter problem? Can you please help.
    Thank you

  12. I just want to say that this should not be taken as absolute truth. I've read through many forums of very experienced scapers and they strongly differ on filtration. Some say that you should filter as much as possible, really fill up the filter with filter media, others on the other hand say they have excellent results with putting as little filter material in as necessary and rather focus on water circulation.

    All I know is that both methods seem to work, but not for all.

  13. Which bacteria would you recommend ADA green Bacter or Seachem Stability? Currently using Seachem matrix but still deciding on the bacteria 😅.

  14. Nice video! can i ask you something about the media… i'm confusing what media should i buy… Seacem Matrix or Eheim subs pro… what media do u recommand more and can u also tell me the reason why that media is better! thank you ^^

  15. Hi i have fish tank 300 liters 120×59×49 i have to external filter one serie 3 2080 xl (1700 liter /hour) and one 3 e 600 (1250 liters/ hour ) is to much flow for plant?

  16. Have seen many people currently bashing sponges in canisters. But its the one filtration method that I find works the best – for cleaning and just ease of general maintenance.

  17. very informative video. Anyway what type of filter can you recommend for my 7L nano tank? Is the hang on enough filter good enough for it? Thank you, from Phillippines 😊😇

  18. How much TDS is important in water chemistry for planted tank ???
    If yes , does it have standard amount ?

  19. Look at this guy Balázs sitting in the middle of all these fine aqariums.
    You've given us some very useful information i'm going to need hopefully in the near future.
    I'll get back on this video again. Thanks !

  20. Hey Balazs, your shows are the best! I have bought the oase biomaster 350 for my ada 60p. I'm now starting to think that the flow might be just too high.. As i have replaced the original UGLY plastic outflow with stainless steel ones, could you suggest how to reduce the flow now?

  21. If I will buy an Oase Biomaster 600 thermo for my ADA 90 P, how much purigen and how much Seachem matrix shall I buy? I will fill it up with only Matrix except for the fine filter in the top.

  22. I'm using sponge filters if I need to used anything else I have power head filter… The plants filter the water

  23. Hi, Balazs, hope you hasn't gone for holiday yet, quick question: if the seachem matrix turn brownish look (instead of cool white grey). Is that a sign for replacement. Is yours brownish after few weeks/months?

  24. Hi, i have 180 liters tropical fish tank, what filter do you recommend to me? JBL e1500 or Oase biomaster350?

  25. how do these oase filters compare to let's say the ada super jet filters(i know they're super expensive)? by the way what light are you using on the cube tank @ 12:28? looks beautiful!

  26. Any thoughts on hang on the back filters? I have a 30 gal tank but have been thinking about switching to a canister filter

  27. Wery insitefull awsome video balazsn as always and fun to watch mate 😍👌tnx for doing it and would love to know more about CO2 INJECTION ??even nickey you tube made a video about it depending what plants u use is not always nessesery 😊.i started my second tank first week doing wery well using eheim 250 classic wery good filter ( reason) (5 star )cose realy quiet and in my bedroom 100 l showtank with internal hydra 30 filter extra for flow using testing (seachem purigen stability)😊👌

  28. Beautiful Tanks !!! Anyone who is critical of this site then you need glasses – I know having CO2 tanks is the best way to go for real healthy plants , I'm still using bottle fert's ….what I didn't know is my Eheim Classic 2215 that's rated too do 200 liters is probably not strong enough for a 160 liter tank – and I haven't heard that it's better to have both inlet and outlet on same side – I'm going to try this – and maybe get a second filter.

  29. Why didn't you talk about hang on the back type filters at all?

    I love the music you used, and the info you gave

  30. My biggest issue with these high society aquascape tanks is they over complicates things made to sell us products. That is why they have the same same kind of scape scenes. My low tech tank have hang on back filter without filter, just to create flow. My plants surface area is enough to colonize the bacteria to process ammonia from decaying plants and waste from fish. Why I don’t use filter is because I want to prevent live feed like copepods, daphnia, infusoria to get filtered. I challenge you all to create a pond style (self sustaining) yet beautiful scapes like the one they have now. Hint, no filter, some flow, paludarium style.

  31. Big fan of your channel, amazing information and most importantly, put me on the correct path to getting the system dynamics started correctly. can’t thank you guys enough for that 😍

    I’ve a question though, with regards to the flow, i’m on a 60p and have an Oase 350 hooked up, do you limit the flow of the output? Appreciate the advice. 😁

  32. Hi, I’m beginner of freshwater currently I’m was complicated about filter media. Not much brand is selling in my country. How about seachem brand does it good? And which media should I get? Thank you

  33. Hello .. i would like to get more informations about planted tanks and what do i need in general to make a good one .. and i dont think i have any of your products in my country so do you have a website so i can order ? im going to build my tank after 2 weeks from now and i would love to get all tips from you .. thanks fro your time

  34. Hey, this is not bla bla, love you sharing your knowledge! I have 200x70x60(H) cm tank and I use two Oase 600 with opposite filter in- and outlets, as you explained. Works perfectly! I clean the the pre=filter once a week and the main filter canisters every 6 months only. Fantastic shop btw! Edit: Forgot to ask whether you can recommend the Vuppa skimmer for a 840l tank?

  35. Hi Balazs if i have RO water can i clean the filter with( Osmosis wather) or is beter with water from fish tank

  36. eheim skimmer 350 or lily pipe in/out flow for 100 litre aquarium ? Tell me what to do 🙂 allrerady have 2 filters in and out the aqua 🙂

  37. I have already ordered a 240l full optiwhite tank.

    I think two filters Eheim Professionel 4+ 2275 they can handle without a problem.
    I will do biological and chemical on one and in the second I will have mechanical.
    I think that such a set will easily cope.
    Thank you Green Aqua for inspiration.
    Greetings from Poland ❤ 👍

  38. Great video. However, I've always understood that having opposing flows across an aquarium is a bad idea.
    This is because it will cause discomfort for the fish population in you aquarium.
    I do appreciate that having this set up would assist with filtration.

  39. Please suggest me a best filter for a 2 feet tank. It has water capacity of 58 liters. I am looking for it since 2 days still can’t decide. I was going to buy Oase Biomaster Thermo 250 but then I thought the flow rate is too high. Please help me out to find out the best I can get. N Thanks for the great video I found it really helpful.

  40. Very good video my friend.
    😃🏖️🐠🐳🐬🦑🐙🦀🐋🐟💕🌞hello from 🌞🏖️🐬Greece🦀🐙🦑🐠🐳🐬🦐🌞🏖️🐠🐳🐬🐟🐋🦀🐙🦑🦐🌞🏖️💕

  41. Sziasztok!

    Segítséget szeretnék kérni abban hogy van 1 Tetra EX 600 Plus típusú külső szűrőm. A szűrőtöltettel kapcsolatban szeretném kérdezni: 1. A Seachem Matrix és a Matrix Trop biológiai szűrő közül szerintetek érdemes a drágább Seachem-et venni? Mert sok helyen azt olvasni hogy szinte azonosak.
    2. A szűrőmnek 1 kosarába hány liter biológiai szűrő fér?
    3. Ti hogy állítanátok össze az én szűrőmet? Én arra gondoltam hogy alsó kosár fele gyári szivacs fele TM30, középső kosár teljesen biológiai, felső kosár TM30 Purigen és perlon.

    Választ előre is köszönöm! És nagyon szeretem a videóitokat! Csak így tovább!

  42. Hi, I really like the products and the videos you post about the planted tanks…. Its really nice, but I live in India, how can I get your products?

  43. Hey balazs and green aqua crew! I'm running a 55l scapers tank from dennerle and was thinking of using the oase biomaster thermal 600 as filter. Do you think this is a good choice? And if so. How much sachem matrix and puritan will I need to add? Thanx so far. All you do is really helpfull!

  44. You should've talked about anoxic filtration (denitrification cycle), being that decomposing food and fish feces will produce excess nitrates when compared to trace elements (even potassium), it's a good thing to include in a system to establish a balanced ecology.

  45. Hi! Some scapers say that, too much biological filter media is counterproductive for the planted aquarium. That means, aquarium without or with a few fishes inside need just mechanical filtration (sponges). Otherwise too much bacteria in biological filter media will reduce dramatically nutrients for the plants. I want one heavily planted tank with fishes, but I don't know how much biological filter media is optimal?

  46. Tu ek chutiya aadmi hai . Sala itne paise me ek bike na kharid loon ?
    Aquarium 10 hazar 15 hazar tak theek hai tu sala 1 lakh ka aquarium batata hai

  47. You never mention fluidized beds. I use them in a sump configuration. Canisters get nasty too quickly. What are your thoughts? Then I do a drip system to remove water daily while I have a carbon block system to fill. Small float in sump adds water as water is removed. I haven't done a water change in 8 yrs. But I've never done a planted tank, I'm just taking my aquarium knowledge and trying to apply it to planted tanks. It's going to be a fun project.

  48. Thank you guys! Your channel is a joy to watch and a great help for me as beginner. Thanks! What is the name of the fish at 1:28? It is beautiful.

  49. Trust me you dont have to be rich to achieve a beautiful plated aquarium like these, you dont need any of this stuff, understand water chemistry aquatic plant life gas exchange an figure out your own way

  50. May I please ask, at the 13:57min mark of your video, what is the brand/model of the diffuser in the back right corner of the tank? The fine mist looks very effective.

  51. I needed this, thank you. I am in the process of getting everything together for my fist tank, in over 30 years. It will be small, 55 liters and what kind of filter to get was giving me a head ache. Now I know 🙂 Thanks again. Your tutorials are a blessing and your tanks are joyous marvels. Keep on scaping and posting 🙂

  52. I just bought a seachem purigen bag, rinsed it and put it in my filter
    It is releasing white particles in its mesh bag into my water, is it normal?
    Is the white particles harmful to fish and shrimp?
    It has no hole or damage on the bag

  53. Really like your videos and have suscribed to your channel !!
    I just bought a 318lt custom made aquarium and will start a planted aquascape and also add CO2. What is the ideal filter for this tank?
    One Eheim 2080 or two Eheim 2036 ? Do I need around 1500lt/h or more for this tank size?
    Thank you !!!

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