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DIY CO2 System questions.

9K views 16 replies 5 participants last post by  noledoc 
#1 ·
I want to build my own DIY CO2 system for my 55 gallon aquarium. I've found a very good instruction video on YouTube that shows me how to do it, but I have some further questions that were not answered in the video.

Here's the video so you know what I'll be basing my questions from:


In the video in the part about him fitting the check valve into the rubber stopper, he says you can optionally insert an adapter in the rubber stopper, then connect more tubing, and THEN connect the check valve. I was wondering what would be the benefit of using the adapter and extra tubing as opposed to just immediately inserting the check valve into the cap. Does it make a difference?
Another thing I was wondering was how many juice bottles (soda bottles) of the yeast/sugar mixture will I need to create enough CO2 for my 55 gallon aquarium?
And lastly, once his CO2 system is all setup, he has the air tubing run directly into the intake tube of his filter to act as a diffuser. Since I do not want to do this, would a simple air stone work as a good enough diffuser, or should I look for other solutions?

Thanks,
Cornelius1208
 
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#2 · (Edited)
I want to build my own DIY CO2 system for my 55 gallon aquarium. I've found a very good instruction video on YouTube that shows me how to do it, but I have some further questions that were not answered in the video.

Here's the video so you know what I'll be basing my questions from:
YouTube - How To Build Your Own Aquarium CO2 Unit

In the video in the part about him fitting the check valve into the rubber stopper, he says you can optionally insert an adapter in the rubber stopper, then connect more tubing, and THEN connect the check valve. I was wondering what would be the benefit of using the adapter and extra tubing as opposed to just immediately inserting the check valve into the cap. Does it make a difference?
Another thing I was wondering was how many juice bottles (soda bottles) of the yeast/sugar mixture will I need to create enough CO2 for my 55 gallon aquarium?
And lastly, once his CO2 system is all setup, he has the air tubing run directly into the intake tube of his filter to act as a diffuser. Since I do not want to do this, would a simple air stone work as a good enough diffuser, or should I look for other solutions?

Thanks,
Cornelius1208
I'll Give you my thoughts.
I would use the adapter and then five or six inches of hose, then place the check valve. This way, should the check valve need replacing as they do on occasion, you would not have to remove it from the stopper which could result in the check valve not fitting as snuggly after doing this a few times and this could then allow CO2 to escape before it reaches the tank as well as preventing the solution of yeast/sugar from possibly clogging the check valve.
I should think it will take a couple of the bottles for yeast/sugar and perhaps a spare that you could prepare when one or the other becomes low but perhaps they would both run low at similar rate? Don't Know.
I would purchase a diffuser for the CO2 rather than an airstone. the bubbles from airstone would be too big and would quickly burst when reaching the surface (also quickly) and thus the CO2 would escape more quickly. Hope some of this helps.
 
#5 ·
Ok great, that's exactly the info I wanted to hear on where I place the check valve. And I bought two 3 liter bottles today to use. Would making a solution with ratios proportionate to this size bottle be ok for my 55 gallon, or should I make just as much as I would if I were using 2 liter bottles? About the diffuser, can you show me a good glass CO2 diffuser? I'd like a nice one if it's going to help me that much more than a simple air stone would, but am not sure what to look for. Would this be a good diffuser?

Co2 Dispenser Aquarium Fish Tank Carbon Dioxide Diffuser - Wholesale Factory Direct

When I orginally made mine I was having leaks between the air hose and bottle top, but I'm not using rubber stoppers either. But now I got a good seal by inserting the check valve directly into the plastic bottle cap and and using epoxy around it to stop leaks. I let it dry for 48hrs and I have't had a leak since. But eventually you may have yeast/sugar build up but I have been using mine for months and months and still works fine. So if you do glue your check valves into the caps then you just go buy some more 2 liters or find a way to clean the ones you have.

I don't know how many plants you have in your 55g but I think 2 -2 liters will be fine and then the 12/16 ounce soda bottle for the gas separator/bubble counter. I use 2 cups a sugar in each 2 liter and 1/2 tsp yeast in one and 1 tsp in the other. The most important step is making sure you get the temperature hot enough..they say warm water but you really need hot. You can see on that back of the yeast package at what temp it takes to make it react..I try to get it around 116-117 degrees. I dissolve the sugar first in the hot water by shaking then add the yeast and shake no more. Then give it a while to build up enough gas to make it to the end of the airline. (this is what I used in my planted 37g...was a little too much for it but probably right for 55g)

I recommend the glass diffusers because if you use a regular airstone the CO2 will go right out of the water and you want it to be there long enough for you plants to use. You will be able to see the little bubbles build up on the surface of the water.You could use a regular air stone if you are just interested in lowering you pH. It will still drop your pH. I have seen a white air stone at Petco/smart that is for the BiOrb tanks that seems to have the fine holes need to disperse CO2 properly but since BiOrb stuff is a rip off you may just want to start with the right thing..a glass diffuser.

Also I recommend spending the extra cents to buy the brass t-valve..the plastic ones tend to leak.
In my 55, I have a good amount of plants, but I'd eventually like to get more, so I would like to have a decent amount of C02. And I did not know that about making the water super hot! I thought it was just lukewarm; thanks for telling me that. I heard CO2 was going to lower my pH, but by how much exactly? My pH is around the 7.3 range, so is the CO2 going to make my tank really acidic, and once I hook up the system, will it change the pH drastically and harm my fish? And what do you mean by saying the BiOrb air stone is a rip off? Do they not work very well? And what would you recommend as far as glass diffusers as well?
 
#3 ·
When I orginally made mine I was having leaks between the air hose and bottle top, but I'm not using rubber stoppers either. But now I got a good seal by inserting the check valve directly into the plastic bottle cap and and using epoxy around it to stop leaks. I let it dry for 48hrs and I have't had a leak since. But eventually you may have yeast/sugar build up but I have been using mine for months and months and still works fine. So if you do glue your check valves into the caps then you just go buy some more 2 liters or find a way to clean the ones you have.

I don't know how many plants you have in your 55g but I think 2 -2 liters will be fine and then the 12/16 ounce soda bottle for the gas separator/bubble counter. I use 2 cups a sugar in each 2 liter and 1/2 tsp yeast in one and 1 tsp in the other. The most important step is making sure you get the temperature hot enough..they say warm water but you really need hot. You can see on that back of the yeast package at what temp it takes to make it react..I try to get it around 116-117 degrees. I dissolve the sugar first in the hot water by shaking then add the yeast and shake no more. Then give it a while to build up enough gas to make it to the end of the airline. (this is what I used in my planted 37g...was a little too much for it but probably right for 55g)

I recommend the glass diffusers because if you use a regular airstone the CO2 will go right out of the water and you want it to be there long enough for you plants to use. You will be able to see the little bubbles build up on the surface of the water.You could use a regular air stone if you are just interested in lowering you pH. It will still drop your pH. I have seen a white air stone at Petco/smart that is for the BiOrb tanks that seems to have the fine holes need to disperse CO2 properly but since BiOrb stuff is a rip off you may just want to start with the right thing..a glass diffuser.

Also I recommend spending the extra cents to buy the brass t-valve..the plastic ones tend to leak.
 

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#6 ·
OH another thing I forgot to ask you dfbiggs was what is the importance of the bubble counter? Is it absolutely necessary or is just strongly recommended. What would be the benefit of me making one?
 
#7 ·
Would agree with brass fittings and possibly brass adapter, as well as using tubing such as silicone rather than airline tubing which could deteriorate from effects of fermentation process. I have heard of this happening with those who use airline tubing and also reprts of airline tubing becoming clogged over time more readily due also to the fermentation process.Airline tubing may also not be suitable for pressure created over the long haul.
Not knowing how the fermentation process affects plastic over time,, I would use glass diffuser which might be more suitable and easier to clean.
 
#8 · (Edited)
Yeah the water temp was really the biggest problem I encountered because people kept saying lukewarm. There is a range you want to stay in because if you make it too hot it will fizzle out fast or kill the bacteria (yeast). Also I was impatient with letting the gas build up. Before you see bubbles come through your glass diffusor a foam of yeast/sugar layer will build up on the top of your water. After it gets about 1 inch thick it will start working its way through the airline.

Just to give you an idea my tap water is a steady 7.9-8.0 pH and say I ran the system starting in the morning by night time is can drop ridiculously like 8 to 6.5. That is the downfall with the DIY because there is no regulator normally. What I did to have more control was run my CO2 Air line through a gang valve and adjust the lever to the lowest setting. I turned mine completely off overnight too or you would wake up and you pH would be 6.0. And of course mess with your sugar/yeast mixture to make it work for you. Remember the more yeast the faster it wil eat your sugar and the more often you will have to replace the mixture. I was replacing mine once a week or every week and a half.

You will want to figure out how to run a steady CO2 injection before you add fish. It's really the easiest if you have fish that require soft water.

I say Biorb is a rip off because you can get an air stone for 99cents but since Biorb is the newest trendy thing they can charge you $4 for an air stone. I haven't tried one. I kind of boycott BiOrb and there bubble aquariums because their target market is people who care more about looks than quality of life for fish :)

As far as glass diffusers I get mine from ebay. You can look around for others this is just an example. Here is a link.
Live Aquarium Fish Tank Aquatic Plant CO2 Diffuser-AT30 - eBay (item 190453492161 end time Nov-05-10 20:43:06 PDT)

There are many fancy ones to choose from. Some have a bubble cou nter right in them. Also know when you see nano diffusers they are a bit smaller. I have one nano and 2 like the one in this pic. I almost like the nano better just because it is easier to hide. Be gentle with these things they break very very easy..lol.

The benefit of the bubble counter is to get a steady rate of flow. If you didn't have one you wouldn't be able to see if your mixture was making gas unless it was coming from the diffuser. And sometimes your diffusor will get clogged with debris and you would think you needed a new mixture when you really needed to clean your diffuser. Plus it will teach you at what rate you need to keep your CO2. Some say 1 bubble per second is sufficient but I was trying to keep mine as slow as possible to make just enough to push through. It would last long this way and wouldn't give me such a huge pH swing.

Hope I answered everything for you.
 
#11 ·
Thanks, I took back all my plastic adapters and got brass ones. =)
But crap, what if I already have fish in my tank? Would starting CO2 not be a good idea?
And since I have a 55, would getting a nano glass diffuser not be recommended? If not, what size should I get? I'd like to get something that I can hide among the decor...
And I got myself a bottle for a bubble counter too. I almost have all the parts and I'll be ready to assemble everything. =)
But what I AM missing though is the rubber stoppers mentioned in the video I posted. I'd rather not use silicon to seal the tube in the cap that comes with the bottle, I'd rather use the rubber stoppers. It seems a lot more convenient to use the stoppers, and I found them online for like 80 cents but shipping was a ridiculous $6.00! So I was wondering, does anyone knows any stores where I can buy them so I don't have to order the online?
 
#12 ·
Well from looking at your list of inhabitants you should keep you pH above 7. However I don't know what pH your fish require. But if you go below 7 after long term or sometimes short term depending on your snail health their shell will deteriorate with the acidic water. Just keep alot of calcium in their diet as you figure out how to stabilize you CO2 system. I'm not going to say it is safe for you to start a DIY CO2 system in a tank with inhabitants..I would recommend you check your parameters often. When I first started I did it every 2 hours. It can drop quick and of course you know pH swings are bad for any fish/inverts. In my opinion I think fish are more sensitive to swings.

If you get the nano with the 2 bottle set up it will have a constant higher flow because it is coming out of a smaller opening..with the other (like the pic I sent you) it will have a high flow also but with the diffuser a slight bit larger it will take more pressure to push through and will be easier to slow down. Not really a big deal at all. And I wouldnt worry about size so much unless you are using it in a tank 20g or less. It will be easy to hide either in a 55g.

I had the same problem with the rubber stoppers. I looked all over Ace Hardware where people told me to get them and didn't see anything that would work..so thats when I decided to use the bottle caps.

Side note: No matter if you use stoppers or bottle caps it will help if you get a couple extra so you can shake the mixture because the others are attached to your system..just something that is forgotten sometimes
 
#13 ·
The majority of my fish actually prefer a neutral to slightly acidic water range, but you're right about the snails. What would you recommend to be the most efficient way to give snails calcium?
And I ordered two nano diffusers in a joint pack for a good price that I'm pretty excited about. I'm going to give in and get the stoppers too because I really want those. I'm going to hate paying the shipping though...

But thanks dfbiggs and 1077 for all your help, I hope I'm not asking too many questions!
 
#14 ·
Your really going to have to try and keep the pH above 7. But google a list of foods high in calcium..spinach is normally at the top of the list. But you'll want to change it up. So to add calcium to the water there is liquid calcium made by Kent which you don't want to overdose. I'd say the more safe route is to put a cuttlebone in the tank..you can get them in the bird section of pet stores. They will slowly release it instead of dumping it in all at once. Or alot of people use seashells.

Do you have a GH/KH/Ca test kit? This is where you will need it.
 
#15 ·
I don't have a test kit for any of those things. =( I grab a cuttle bone today if I have time. I've also heard of people using the Reptomin Reptoguard Turle Health Conditioner blocks, because it's almost all calcium sulfate hemihydrate, or something like that. Would that be a good idea, and do you think it would actually work?
 
#17 ·
Question and possible idea regarding CO2

I've wondered if it makes sense to allow CO2 bubbles to be trapped under some sort of underwater shelf in the tank so that they form a pocket of CO2. This would allow a continuous gas/liquid interface. With bubbles simply rising thru the water there is very little time for the gas to diffuse into the H2O.
I do wonder if it would be difficult to control the actual amount of CO2 and leave the ph to be driven where it shouldn't go. I think one could learn how to control this but it might take time. One thing, it seems that it would maybe allow for very little CO2 to go a long way.
One more thing, Al Gore would be very proud. He did after all invent CO2. :-D
Thanks
Paul
 
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