Many of you guys, have asked us in the comments, to do a tutorial about CO2, about fertilization and about water parameters. We’re listening to you, here we are. Tutorial at Green Aqua for beginners. Welcome to the beautiful world of aquascaping! So, let’s begin with the CO2 system. What do you need to know about the CO2 canister? When you’re traveling with this, please make sure that you don’t put it in direct sunlight. This guys doesn’t like to be expanded or contracted. The CO2 pressure reducer takes 50 Bars of pressure and it reduces it to a 2 to 4 Bar pressure. If you don’t have the sealing ring inside, you’re gonna be in trouble, because the CO2 is a very tiny particle gas and it can escape from that. A 2 kg bottle for a 60 liter tank probably lasts 6-8 months, depending on what kind of CO2 system you have. CO2 is very important for the plant photosynthesis. About 1/4 of the plants will survive, will do okay without CO2. They will not thrive, they will not look perfect, But some of them will do fine with a CO2 supplement. The best CO2 supplement that I know, is the Seachem Excel. You want the CO2 to be in the water, before the lights go on, because plants will start to photosynthetize exactly at the moment when they’ll get the light. And they will need the CO2. This tap will control how much pressure you want to give to the output. The needle valve lets you control the exact amount of the CO2, that leaves. At this point, where you have to connect the hose, that goes to the aquarium. This is a pressure tolerant hose. Many people are not using this, but I would recommend you, to use it. And then, we are ready with the third part of the CO2 system. The solenoid valve is used in the system, to stop the CO2 for the night. When it gets electricity, it will let the gas through. When it doesn’t get it, it will not let the gas through. Did you hear that? Zero. Why is it zero? That was my eyeglasses. Why is it zero? Because this tap is not open. Bottle, pressure reducer, pressure tolerant hose, solenoid valve. The check valve has a little arrow on it, which will indicate the direction of the flow. The check valve will prevent the water from flowing back from the aquarium into this system here. The bubble counter is good for you guys, to measure how much CO2 goes into your tank. 40-60 bubbles per minute coming out from the bottom of this would be good for an average tank. You can fill it up with water, but I would suggest you to use bubble counter solution. It’s heavier than water. This solution will stay in your bubble counter for much longer. Filling up until say, 4/3. Four thirds? Three quarters. What am I talking about? This whole thing is not very smooth, is it? Let me tell you quickly, what we have here at Green Aqua. We have a 2 kg bottle. We have the pressure reducer, with the two indicators. A needle valve and a big tap, that I will show you how to open it. And we have a solenoid valve. ADA check valve, ADA bubble counter. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. And we have an Aquario Neo diffuser, small diffuser in there. This is a Neo CO2 diffuser, an acrylic dissuser. It’s quite good, we like it, we use it a lot in small tanks. I kind of think that this is a good budget alternative. This diffuser is an ADA Pollen Glass 30 diffuser, which I would probably use for a 60 liter tank as well. It’s too big for a 10 liter tank, but you could use it if you wanted to. If you’re planning to buy a bigger tank later, you could buy this diffuser and just use it later. This is a lot, right? Surface movement is important, because you need to make sure, that there’s proper gas exchange on the surface. You do not want to draw out the CO2 by moving the surface too much, like stirring the surface. For example, if the lily pipe from the external filter is too high, too close to the surface, then it will draw out the CO2. If you want a very efficient system, you should use a CO2 external reactor. We have the reactor, which is my very personal favorite. Much more CO2 goes into this tank and it’s being dissolved completely, because the bubbles are gonna go up, the water is being pushed down the reactor. So the bubbles are going against the water. It’s a 100% dissolve rate. We don’t need a bubble counter for this solution, but we’re using one for show purposes obviously. We have the Beetle Counter here from ADA. You need a strong filter, to run with that reactor. If your filter is not strong enough, to pump CO2-enriched water out of the reactor and CO2 gas will just go up to the top of the reactor and just get there. We have external reactor below all of our (big) tanks. How do we measure, how much CO2 we have in the system? You’ve got to have a drop checker. You’ve got an indicator solution in the drop checker. And this solution is blue, when there’s not enough CO2. It’s green when there’s little CO2, it’s lime green, when it’s optimal and it’s yellow, when it’s too much. Place it in the water, near the surface. Somewhere not above this CO2 diffuser. One problem is that this whole system is not accurate to the minute. You can see that the drop checker is lime green color. And it shows the status of the CO2 two hours before. This is a lot of delay. It will take about two or three hours for the CO2 level to go up from 0 to 30 ppm, the ideal measurement. So you need to switch on your CO2 two hours before the lights. This way, you will need two timers. We have a central timer here. The central timer switches on at 7 o’clock every morning. The lights will switch on at 9:30. Everything will switch off at the same time. So CO2 and lights will switch off at the same time, at 5 o’clock. You don’t want to fluctuate the CO2. So don’t play around with the CO2 needle valve too much. Adjust it to a certain bubble count and leave it there for a couple of days. Observe what’s happening! If you do sudden changes with the CO2 system with the bubble count, you will have algae, CO2 related algae. I already showed you the Green Aqua drop checker solution. And I didn’t show you the Green Aqua nano drop checker. We have a small drop checker for small aquariums. The one that I used in the nano tank was way too big. I just wanted to use that for you guys, to see how a drop checker is used. This is a diffuser for air. Do you need aeration in an aquarium? I would say that you don’t need aeration in a Nature Aquarium. You don’t need an air-pump, you don’t need anything like that. But, if you wanna be on the safe side, you might want to put this on timer for the night. Please do not leave your system without CO2, even for a day. Your plants will suffer. A lot of CO2 will be toxic to your fish. If you have more, than 30 ppm CO2 in the system, hence the drop checker solution is yellow, Your fish will start to suffer, they will start to suffocate. Don’t forget, that the CO2 will decrease the pH. Decreasing the pH of your aquarium water will result in filtration problems. 6.2 is already borderline, too small. And the filter bacteria will start to suffer. Now let’s talk about the ADA gear! That we have right here! We have the Do!Aqua, which is a brand, that has been discontinued by ADA. The DOOA brand comes instead. Mini diffuser for small aquariums. This looks really sexy. ADA has also got a very nice CO2 regulator, which has only one indicator. As I told you before, the CO2 is in the liquid form in this canister. Transport it in vertical position, and always use it in vertical position. Do not let your children play with it. That’s it! CO2 done! Fertilization is really, really easy. What you have to do, is you have to get some good quality ferts, that are concentrated, or not concentrated, but are well-thought. And you will have to add them to your aquarium daily or every second day, or every week, depending on what kind of system you have. There are basically two types of ferts, that your plants will need. They will need the Macro and they will need the Micro ferts. The Micro ferts are basically trace elements. The biggest component of all of those is Iron. Iron is much needed by the plants, and actually it’s needed for the red plants even more. We, at Green Aqua have a very good fertilizer, called Micro. I have to dose one pump or one ml. per 20 liters of aquarium water. The ADA Mineral is kind of the equivalent, but not really, of the Green Aqua Micro fertilizer. The macro fertilizers are Potassium, Phosphate and Nitrogen, in form of Nitrates, usually. The Brighty K has Potassium in it. We’re using the Green Aqua ferts, when we want accentuated plant growth, we want nice red colors, we want lush growth. We’re using the ADA, when we wanna go for finesse, when we want to go for the Nature Aquarium very slow growth feeling and we quite like that. I’m trying to reach the 30 ppm Nitrate levels. And the 3 ppm for the Phosphate levels. Please try to do the 50% water change. If you do not do that, your nutrients’ level will just grow and grow and grow. Carbon suppliments are also considered kind of fertilizing, because Carbon is also needed by the plants. I would suggest you to buy quality fertilizers. Do not buys the cheapest fertilizers, because they’re cheap for a reason. They basically contain a lot of water and they dilute it. As you can see, we have a few ferts here, at Green Aqua. What you see here and then on the other side, with the ADA shelf, is only half of it. We have Tropica, we have Dennerle, we have Seachem ferts, etc, etc. I’ve got two more ferts, that I wanna show you. One of them is the Easy-Life Profito, which is a really good fert for beginners. It’s really cheap. And I wanted to show you the Flourish Phosphors, which is a very, very good Phosphate addition to your tank, if you wanna have something, to fight the green algae. Usually, when you’re using a base layer fertilizing substrate, you will get enough nutrients from the base layer fertilizing substrate. If that substrate depletes for some reason, for example you’ve been running your tank two or maybe more years, then you would need the NutriBalls, the Dennerle NutriBalls. And you’ve got rootsticks from ADA and you can just put them into depleted soil. The plants will get the nutrients from there. Okay, enough of the fertilization topic! Let’s talk about water parameters! Most of the plants, that we are using in the aquarium are coming from the equatorial region. And the water there is very soft. What we do here in Hungary, is that we’re buying Reverse Osmosis systems. RO water is usually TDS 10 to 20. And then you can remineralize it to 120. Here at Green Aqua, we’re using the Green Aqua GH plus. How do you measure GH? You got a test for that. But I’ve got a better solution. You can measure the TDS, which is the Total Dissolved Solids. If you keep your TDS at around 120, then you have a GH of around 3, which is ideal, so you should be okay. About the KH, many people were asking us about the KH. We think that GH is more important. If you have the salts in there, then the buffer for the KH is already done. We are here in the water test goodies store! I’m not against tests, but I wouldn’t want to use them actually. The only test that I’m using is the TDS, or a pH test. So let me show you, how a TDS meter works! And Csabi has brought me some GH plus. So there’s an on/off button on it. Push it, it says 0 ppm on it. Put it in, 62 ppm. Seiryu stones are leeching a lot of Calcium into the water. 132. 164. You can actually see that the general hardness in that tank is much higher, because of the Seiryu stones. Let’s measure the TDS of the reverse osmosis water! And Csabi was kind enough, to bring me one. 7. Our reverse osmosis, it’s quite cool. And then I’m gonna drink it. Perfect H2O. The Green Aqua GH plus. Very scientific. I’m just gonna put it in the water. I’m gonna put a lot now. It’s already 109. 110. Let’s see, where Filipe’s tank is at! 122. Pretty accurate! So 122 for Filipe’s tank, which is destroyed. You can see on the picture. Sorry Filipe! After you used it, you have to just close it back. Don’t leave it open, because if this dries out, they will loose the accuracy. Water treatment heaven at Green Aqua! You’ve got all the different products, that are used for water treatment. If you are using tap water in your tank, you need to get rid of the Chlorine and the heavy metals. Seachem Prime, it comes in different sizes, it will help you to do that. Some people like the Easy-Life Easystart, but that has some bacteria in it, and it can get your water cloudy, so we would prefer to use the Seachem Prime instead. The temperature of the water should be around 22-24 degrees. If you do not have like discus fish, or some other fish, that would require the temperature to be higher, or lower. If you have the temperature above 24, that will profit algae, so you don’t do that. So try to keep it as cool as possible. If you would need heating, you can use an external heater like this, But I would prefer the Oase filters, because those filters already have heaters in them. The water temperature: You can actually see the water temperature on the external filter. It’s 25.5°C. It’s because of the summer heat here, in Budapest, as I said. So all tanks are between 25-26°C now. And I’m not happy about it. Okay, I’m drinking water! What happened to Green tea? Things are getting worse at Green Aqua nowadays. So guys, thanks for being here with us, I’m gonna make some order here and I’m gonna say – subscribe if you didn’t do so yet. Thanks for staying here, comment below, let us know what your water parameters are. I’m gonna see if I can help you with anything. And subscribe, if you didn’t do so yet… Did I say that already? I think I did. I’m talking here by myself, alone in this studio too much! Anyways, smash that like button, comment below, thanks for being here! Ciao!


  1. Hi balazs great tutorial.
    One question if u can halp..
    I keep a steady ratio of 10ppm n and 1 ppm p, co2 is about 25-30 ppm… i have hi led lighting (chihiros wrgb) that works around 70% for 6 hours. and i just cant get rid of the green spots algae.. what would you advice to do? Increase the light intensity or just lower bit the co2? Maybe increase the co2? Or maybe even tweek with the ferts?
    Love your channel by the way, thanks a lot : )

  2. Hello from U.K. Great video with awesome information as always. I have mixed rainbow fish, would 22-24 temp be ok for them. Mines a touch higher. Thx

  3. I need advice from the top planted tank pros. I have many successful planted tanks in the 76degree F range. But I cant grow anything in my discus tank witch is at 83 degrees F. What should I try?

  4. I watched the whole thing even though I only speak broke and is all low-tech for me, but it's a great guide. Next thing will be lights right? Great vid

  5. Great video! really informative. just wondering, you guys are dosing Seachem Excel on top of injecting CO2 in the tanks? Is this done daily as well?

  6. can you tell how to prevent or buffering the seiryu stones to raise crazy KH? is soaked with muriatic acid is good to prevent a bit? (without talking RO system)

  7. Nice advices. You look like Mark Ruffalo, and overmore work in green. Do you understand me? Born for green world. Have a nice day.

  8. Thanks Balasz for the video, always some usefull info, even for experienced aquarists.
    I do have one question for you… I keep my Altums at 26°C. Can I lower the temperature to 24° or wouldn"t that be recommended for these fish? I've always learned they need 26 to 28°C. Would love to hear your thoughts on this!
    All the best to you and the Green Aqua team!

  9. Hello sir , I'm Naman from india, sir ada products are not available in my area. But seachem products are available. So which seachem fertilizers i have to use for my planted tank . Please suggest the names of seachem fetilizers which is necessary..🙏

  10. Great video guys. I am waiting for the video about the initial steps with a new aquarium. How many water changes, do I need Purigen, how to avoid alge… 😉

  11. Always love your videos, Balasz. Both George and Green Aqua have started my interest in scaping.

    I'm currently battling GSA and it keeps coming back. My lights are adjusted to roughly 2.5 watts per gallon and the CO2 level should be good as the drop checker is lime green. Just to clarify that you mentioned phosphates should be kept at 3ppm? Does this mean it's at the 3.0 mark on the Seachem Phosphate test kit grading? Any advice to battle GSA will be helpful.

  12. Hi Balazs Farkas, I was told that nano tank nature aquarium is for beginners however i find it hard to control the water parameters and constantly having algae issues. Another local aquascaper told me its best to start with 60p tank to better manage the water parameters. Is the nano tank really is for beginners? *help out a miserable beginner aquascape here

  13. For me, I've never had the need to use CO2 or fertilizer, My plants grow just fine, usually to well. Right out the top of the tank.

  14. Excelent video 😊👌 exacly what i needed to know and realy enjoyable 💪🙂💪.my temp of bouth tanks 70 l and 100 l are between 24 /25celcius ic some algee on the rocks i have only a miner thing i can use snails for it, it whas about 28 Celcius 2 weeks ago do to temp 39 in the netherlands realy unsual for the netherlands .i have no problems with algee non in it tnx to twinstar nano plus non Co2 injected . one question about firtelizing in some info it s says 10ml for 100l weekly is that corect or dose less mll daily? Professianal or iron witch day i start from monday depending on threre dificiency on plants leaves??

  15. So when the Phosphate in your tank crashes to 0, and you add a 1/2 teaspoon to bring it up to 5ppm, then it is back to measuring 0 again just 4hrs later. What should you do?

    Most dosing guidelines are N:P:K @ 10:1:7

    not 10:99:7

  16. hmm I don't buy that a PH lower then 6.2 or 6.4 affects directly bacterial efficiency at processing fish waste, maybe indirectly by reducing dissolved oxygen….good video tho, Im not trying to bash on you. My anecdotal experience would would not agree with said statement.

  17. Great rich article. Congratulations. For me, one of the best channels on you tube. I have 2 cylinders – 1.5kg co2 and I use them alternately. Filling in PLN costs PLN 14 (3.5 euros). It takes literally 5 m. At the moment I use fertilizer tropica sp. Nutrition. Substrate Adwented Soil. Glass Opti White. 125 letters. greetings .PS. What's your name 😛 ?

  18. Wow, great video, just back from holiday. Soooo much useful information. Thanks for sharing. New season is kicking off on a high.

  19. Slight hearing problem here – I didn't catch what you suggested filling the bubble counter with rather than water. Did you say 'bubble counter solution'?

  20. I want to ask about GH. I tried to plant rotala h'ra, I used RO water, my question is if I set the Water Parameters at TDS 120. At the time after Water Change, should TDS 120 be maintained until one week later? Or what is the maximum TDS that must be maintained to make red plants until it is time to replace the water (180-200)?

  21. Hi, I use ro water and re mineralise to 100 tds after I do a 50% weekly water change my tank tds is around 250 due to sireyu stone. Would you lower the the amount of ro re mineralisation to say 50 to bring the tank even lower? Thanks

  22. What is you opinion on Easylife Profitto & Ferro? In Australia we don't have access to a great range of ferts, ADA is very expensive and we cant get Tropica liquid ferts here. The only other option is Seachem ferts.

  23. Very informative! I don't understand how TDS meter can be used to ensure GH is within the correct range. Could you please elaborate this, together with the assumptions (e.g. must use RO)?

    Also, you don't use nutrient test kits. Is it because it's easy to calculate knowing the tank volume and the plant density?

    – Greetings from Indonesia

  24. I see you tightening the regulator with a wrench, is it allowed? I got a lot of information from the internet and the seller that it would damage the regulator seal.

  25. i bought grass from your store : Dennerle Eleocharis parvula mini pusilla in-Vitro and I put it into newly setup tank (2 weeks) with baseLayer with nutrines. Do i need to fertilize the water still ? I do not have co2 yet, even it is written on plantInfo, it needs 22 ppm co2. Will this grass work for me without co2? and if yes,… do I need to add fertilizers ? I only have this grass inside tank, nothing else for now. My tank includes built in lights 1×6500 kelvin and 1x 8000k which runs 7 hours/day. Tank is 240L from Juweil. Oh yes.. and TDS tester from your store shows me 240 ppm….

  26. Balazs u have so much knowledge that is not even fair,so calm,straight to the point,super nice videos and equipment…jizzz,all in one!!!

  27. Will dosing Macro and Micro effect your TDS / GH? Because my tap water TDS is around 70-75 but some how my tank TDS is all the way at 300+

  28. Great guide thanks just wondering how many hours for co2 and light for a nano tank just setup today and how many bubble per second?


  29. I just need your number and call you to come to my house to do a HUGE aquarium like what I want, then I don't need to think much. Just pay u and the materials.

  30. Balazs great video great content as always. Apologies for late comment on this. Very helpful for those who really love this hobby/profession from their heart. Beautifully explained each and every details whether its related to water column, co2 level or its ferts. I completely do agree what you said about good quality of fetrs its very important the way human needs good and healthy food in terms of their growth or stay healthy absolutely well explained. Well I have something in my mind let me ask you if that's possible. I would like you use the Green Aqua fetrs micro and macro as you know I'm from India is there any way-out to ship to India my address? Or it will be expensive for me to have it from there in terms of shipping and all? Please do let me know. I"m sure I could fill a book with the reasons why I'm grateful to you. Thank you for your insight, for your inspiration and for giving me creative energy to grow and do something new every day.

    Lots of love to team
    Megh (India, Kolkata)

  31. In my tank on summer it will be from 27°C to 31°C only on tank .. so AC is better way with some ice to keep it 23-25°C 🇸🇦🇸🇦

  32. I use pharmaceutical grade vegetable glycerin in my bubble counter and I see it going into my check valve. Would that ever be a problem? I use the ADA check valve.

  33. Just got my ADA Pollen 30 mm today. Have ordered check valve (I think it's called Ruby?), drop checker and beetle counter. My tank has been living without CO2 since it started 5 months ago, I thought I'd try the CO2 out. Will get the CO2 canister, pressure reducer and solenoid when all the glass comes.

  34. So 30ppm is the standard “recommended” for a fully established tank. How about after flooding a dry start, when the Co2 needs to be ramped up much higher? Should I ignore the drop checker and PPM level as I dial back the Co2 each day until the tank is more adjusted to a lower Co2 level?

  35. why do you need nitrate in macro ? if u have fishes, they should provide enough Nitrates. Is this mainly for planted tanks without fishes _?

  36. First off a very good video as always..tanks for putting so much effort into ur work!
    For my new scape i tryed the ADA fertilizer system and they worked good…the only downside to them…and i have to say i do actually think they are indeed watered down quite a bit. Not only are they way more expensive than alternatives but i have to use more of them for less overall minerals in the tank. I like ADA…i use it alot…but their fertilizers are, in my eyes, sadly way to overpriced. I switched back to Aquarebell now and i get the same results for less money. But i think i have to try ur fertilizers for my next tank.

  37. Why not use an automated PH controller like a American Marine Pinpoint Ph controller or any other brand instead of a timer? Wouldn't that keep the ph more stable and create less stress on the fish? Great info BTW and man you guys have some beautiful tanks in there.

  38. I am using TAP water in my planted aquarium, which has TDS = 200 ppm, KH = 7 , and PH = 7,7. I am putting CO2 there, which during day pushes the PH = 7,0 max. Is it possible to have the aquascaping plants like grass : utricularia graminifolia or eleocharis parvula ? I dont quite understand why do I need have soft water, which is only possible to create via RO + remineralizing or mixing RO+tap water. Its not easy to create such water every week and looks to me like overkill. Is it possible to have theese aquascaping like u have without RO water at all , just by having hard tap water + co2 ?

  39. I want to ask about the skimmer! Why is the use of Co2 (Bubbles Counter) when using a skimmer and not using a skimmer? for example, when I don't use a skimmer, 3 Bps is enough. but when I use a 24-hour skimmer I set it to 5 Bps to make the Co2 indicator a lime green (even though there are no ripples on the surface of the aquarium)

  40. Hey everyone at Green Aqua, great info on CO2 and fertilizers! This definitely helped simplify a lot of stuff for me! Just out of curiosity, what do you think of the Walstad method planted tank? It uses no CO2 and no ferts, just organic soil and gravel as substrate, as well as 5000K-ish bulbs usually for lighting. Have you ever tried this method, or have thought about trying it? It would make a great comparison video of low-tech vs high-tech planted tanks! Please let me know what you think, love from Canada!

  41. Thanks for your sharing. It is really helpful.
    But I have question about the on/off method of CO2. 'Keep the CO2 on while the light is on' or 'keep the CO2 on for 24 hours'? which one is best? Someone said if you keeping the CO2 for 24 hours, PH will be more stable which is good for the plants.

  42. Hi Green Aqua
    Question about water getting in to the C02 loop.
    At night, the C02 pressure drops when it is not on, and because of the pressure change, I get water sucked in through the defuser. I have a check valve so no issues there. When the system starts though, because of the water in the loop, the pressure builds up, and my tubes sometimes pop off the peripherals, squirting water and wasting C02.
    Is there a way to prevent this?

  43. I live in Hawai’i. I get high evaporation rate due to warm weather all year round. I’m topping off every day or so. Remineralized RODI water in aquarium, topping off straight RODI water. Keeping TDS from 120-200 then doing water change. I get lots of melting and in my opinion due to warm water? Any tips on growing healthy plants in warm water? I’ve been experimenting with hardier plants and it’s hit or miss so far. Thank you!

  44. Hello from Poland. I've a question. How do you know is TDS 120 ppm corresponds to GH 3? Is there any formula for conversion ppm from TDS to GH? I have 205 ppm in mine tank. I don't know if I'm counting correctly , this result give me 7 GH?I mineralize water to parameters KH 0-1 GH 6-7. PH 5,8 . My RO water have 3-4 ppm in TDS. Please reply for this question . P.S. Great channel, best regards :).

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