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Has anyone used DIY CO2 setups with good results?

14K views 27 replies 17 participants last post by  Grah the great 
#1 ·
Hello, so I have used the basic sugar+yeast method with nano tanks and have never had any problems whatsoever and have achieved good results always.

Now they are selling these new DIY kits that use citric acid and soda and even come with a solenoid valve>

https://www.amazon.com/ZRDR-Aquariu...uarium+co2+diy+solenoid&qid=1590680620&sr=8-5

Has anyone used them? It seems like a functional solution to replace expensive co2 equipments. What do you think?

Also do you normally measure your co2 in the tank? What method do you use?


I'm planning to set up a 30 gal. Thanks
 
#2 ·
I've not used any of those kits, but it seems to me that they won't really save you that much (if any) money in the long run on a large tank. I don't know if anyone has done a cost analysis to see what the breakpoints are in that situation, ie. large vs small and/or short/long term usage.



I did do diy with the yeast/sugar setup and got very good and consistent results once I dialed in my system. It wasn't even that much work once I figured it out. I was using quite a bit of sugar, though I never added it all up to see how much money it was costing me to maintain.
 
#6 ·
It's more an experiment than a long term solution because you can't regulate how much, or how little CO2 is produced, it all depends on what strain of yeast, if it is fresh, or old, whether it likes the sugar, or not, whether it is warm, or cold, and most of all you can't turn it off at night as you can with pressurized CO2 either manually, or automatically with a solenoid and timer. Pressurized CO2 you can regulate very exactly, and you can ensure you add it when, and how much you want.
 
#7 ·
The OP is asking about baking soda + citric acid kits.



I tried one of the ZRDR kits, the valve was a dud and it doesn't include a magnet. I've had good results with this kit. You can get the solenoid for ~$16. It costs a little more but you get Prime shipping rather than waiting for it to float over from China. It's very easy to use; just mix up the citric acid and baking soda bottles per the directions, screw them on, give the citric acid bottle a good squeeze to start the siphon, then open and close the valve a few times to siphon in more citric acid and build up the CO2 to working pressure. Then it's ready to be attached to your bubble counter/diffuser. I do 1-ish bubble per second in my 20g with that fluval bubble counter.



I've found that the output is usually consistent and I don't have to fiddle with the valve until it runs low. Sometimes it will siphon in too much citric acid and keep building up pressure, the kit I linked to includes a magnet you can use to raise the input hose and stop the siphon if that happens. If you can afford 1 cup baking soda + 1 cup citric acid every 2-3 weeks and don't mind spending a few minutes on maintenance it works much better than yeast setups.
 
#8 ·
For last week i am experimenting with DIY CO2. I am currently using one 2 liter bottle setup with 2 cups of sugar, 1 tsp of baking soda and at about 1/4 tsp of yeast for my 10 gallon tank. It supposed to last for 2 weeks, but I will still see it. I have glass diffusor which makes all the difference I think. ANd my drop checker is green at the moment , darker green but I am ok with it. If you plan to go with it, use silicon kit fo seal tubing, make sure you have setup secondary exit valve in air for nightime as this don't stop. When I made good container (this is where you will have most problems) system starts bubling in couple of hours. For 30 gallon tank it might be too little co2 made this way and as I think it is more for smaller tanks where pressurizzed systed are too expensive.
But, since you have 30 gallon tank, I am thinking that with time cost of mats for this big tank might be too much. I would go with refillable pressurized co2 in your case. But it is investment that is for sure.

Bump: Ah yea, I also tried baking soda and citric acid, but that system is so inconsistient, that I droped it fast.
 
#9 ·
Unfortunately I did not have good results. The problem for me was consistency. Sometimes less CO2 - sometimes more CO2 was a recipe for algae. Even using a compressed CO2 mini cartridge the amount would vary because I was using a single stage regulator and as pressure dropped in the cartridge the bps would decrease necessitating constant adjustments. Now for my low tech tank I use a bell style reactor in the tank which gets filled up once in the morning to diffuse into the tank and that’s it. My CO2 is waaay below 30 ppm, but I feel like I am better off with less CO2 than with unstable CO2!

Reliable way to measure CO2 is with a CO2 drop checker inside of the tank. It only shows you if you CO2 is above/below a target range, usually 30 ppm.
 
#10 ·
Has anyone used them? It seems like a functional solution to replace expensive co2 equipments. What do you think?



Also do you normally measure your co2 in the tank? What method do you use?





I'm planning to set up a 30 gal. Thanks
Because you asked this very question, I'll say, no, it should not be considered a functional replacement for expensive (pressurized?) co2.

One reason is the addressing of your own question. Testing, whats that? Having pressurized is so rock solid that I no longer worry about it until the tank runs out. A bubble counter or perhaps the newfangled flow valves to verify its all flowing is all you need. But back in the day, when I did check, it was via the ph drop method and drop checker. And some loose interpretations of the co2/kh/ph chart. You see, because theres no reliable way to test co2 reliably anyway, you'll soon learn just to keep it steady and stop chasing tests. This url will tell you more than I ever care to type but which I still learn from every visit:
https://www.advancedplantedtank.com/blogs/choosing-co2-why/co2-fine-tuning-3-techniques


Additionally, based on the replies before me and my own experience fiddling with the yeast method (I know, not citric acid), the fundamental idea is still this: All this time you spend fiddling with your co2 is probably better spent fiddling with the plant/tank maintenance instead.

Unless you like fiddling with this sort of stuff, then carry on, science experiment! :)
 
#14 ·
I've been using one except instead of citric acid I'm using white vinegar because it is cheaper.

My main gripe with these DIYs is they advertise that you'll get 6 weeks on a single fill of soda/vinegar(or c. acid). Instead I've seen 1.5 weeks. Had I know that I would not have bothered. I don't mind putzing with refilling them once a month or so, but every week or two is a bit much.

However, I recently read that the key to making them last long is to keep the magnetic bulb in bottle A just below the liquid level. For the life of me I don't know why this would make a difference, but I'm going to give it a go before deciding to write these things off.

Another mystery to me is why there is a little Y-connector in the drop tube in bottle B. Actually I understand the Y-connector, what I don't understand is the reason for the drop tube to go all the way to the bottom of bottle B in the first place. Wouldn't it work just fine if the entire drop tube was stubbed off just a bit below the inside of the bottle's neck?
 
#15 ·
I had four of the commercial plastic units strung together with hose Ts. I found that using boiling hot distilled water with the sugar made it last longer — killing any bacteria. When it cooled, I added Champagne yeast from the brewery shop, which tolerates a really high alcohol content compared to other yeasts. I would alternate refilling them every two weeks to keep the flow study.

Here’s the forty gallon breeder on which I was running them.
 

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#16 ·
CO2 Gen Walmart.

I have the latest iteration of this from Aliexpress. I should've purchased the 2 liter. But I've been using the 1L for a month now. I think it has another week to go. I have the pressurized co2 tank but driving to get a refill is a hassle. I had a feeling that we'll be on lockdown, so I ordered most of my stuff 2 weeks prior including this.

13lb baking soda from Costco is $7.
10lb citric acid is $35

I use 100grams of each for 5 weeks for my 1L setup. It will last me 3.5 years


Note: Aliexpress orders currently takes 3-4 months. So always select DHL for 5-10 day shipping. sometimes, it's $20, sometimes free.
 
#19 · (Edited)
I only have a 15gal, 14 or less with all the rocks and gravel. I run it at 1 bubble per 1.5 seconds only. it's enough to get the hair grass, java moss, christmas moss, and monte carlo to pearl. I started on May 9th. I closed the tank right away after pouring water. it went up to 10kg in 5min and 24 kg later during the day.
 
#18 ·
Hi @Arturosito,

My first planted tank 10+ years ago was a 45 gallon tall (24" tall), I didn't want to spend a lot on a CO2 set-up so I did DIY (sugar & yeast) in two each 2-liter bottles and fed it into the intake of my Aquaclear HOB filter. I found I could grow plants just fine and the CO2 definitely made a difference so I picked up a used CO2 tank, used regulator, a good Ideal needle valve after six months because I got tired of mixing up the yeast / sugar every 5 days or so.

45 tall w/DIY CO2
 
#20 ·
Results varied, it can never beat pressurized which is what I am using now. The plants are lush but I have had a lot of different malfunction issues, people tell you that CO2 released too much = yup, had that happen. That turned out to be a manifold issue, I had the pin leak too, I just couldn't make some of the stuff up. The only thing that hasn't happened is exploding coke bottles, haha, thankfully, but too inconsistent. When it works, it's great. When it doesn't, it's a disaster. I still use it now but on tanks that I don't have fish in, but every 2 or 3 weeks, replacing it has become a very daunting chore.
 
#23 ·
I have spritzed it with soapy water and could not find any leaks. I guess I will have to try submerging the bottles. I just got one of those kits with the gray plastic caps, quick connect fittings and vinyl tubing. One thing I noticed is I have to squeeze bottle A like a gorilla and the meter barely makes it up to the green zone (1 Kg/cm2). I don't know if that has anything to do with it.
 
#24 ·
Guys, In the end I took the professional co2 regulator route and I am so happy with the results, but I have another tank, it is a 3.5 gal nano, I'm sure DIY Co2 might be more than enough here? Anyways, I have just set it up with the classic 2 cups sugar 1 tsp yeast 1 tsp baking soda DIY Recipe.

I have a spare solenoid (it is crap from China, haven't used it yet) Would there be any use using it to maybe save the co2 during the night? Would the plastic bottle explode or something?

Also I am using an airstone as diffuser, is that good enough? I know sometimes the pressure can't push through ceramic diffusers.
 
#25 ·
For my yeast reactors, I use (per 20 ounce soda bottle) 1/4th cup raw sugar, 1/8th tsp each baking soda and corn starch, a tiny amount of fish food, and .45 ml instant yeast (and enough dechlorinated water to mostly fill the bottle...I do not fill all the way to the top of the bottle); I then shake the contents, and if the water surface in the reactor starts to foam within a few minutes the reactor activated correctly). This is enough to provide high tech levels of CO2 in a 5 gallon for over two weeks without a drop in production (though I switch out the reactors at the two week mark just in case...I would recommend keeping track of the restart days on your phone). I also heat the reactors (by placing them in a container with water and an aquarium heater) to stabilize CO2 production.

Also, there is a VERY easy way to make a sealed, CO2 worthy bottle cap...drill a hole in the cap slightly smaller than the CO2 tubing, pull the CO2 tubing through it (ideally by cutting the tubing at an angle first to make it fit through more easily), and you have a CO2 bottle cap that you can connect to your bubble counters and diffusers. I use internal power filters in my tanks and diffuse the CO2 by sticking the end of the tubing into them.
 
#26 ·
So my DIY yeast sugar on my 3.5 nano is doing just fine. In fact, my co2 indicator is yellow (co2 in excess), I have no fish or shrimp, but will add shrimp. How dangerous is this excess to shrimp? Like I said, I have a solenoid which I could hook up to it, but does anyone know if the co2 reactor would explode from built up pressure?
 
#28 ·
High CO2 can suffocate livestock (though exactly when this occurs depends on the critter in question), but an equally significant risk is the PH drop associated with CO2 use. I tried adding ramshorn snails to one of my yeast reactor-driven tanks, and they were dead within a few weeks because the PH was in the mid 6's - even though the GH was 6, the snails evidently could not survive the low PH level. The snails would have been fine had the tank had enough buffering to keep the PH above 7 even after it was reduced by the CO2. Plants take about a month to adjust to altered CO2 levels, so take your time if you do decide to lower your CO2 input - rapid CO2 changes frequently trigger algae (the plants shed sugars and proteins while trying to adjust, the algae take that as an invitation to attach to the stressed leaves...speaking from both experience and research here)
 
#27 ·
For anyone reading, yes, diy Co2 can be used to create nice plants. Check out a channel named TropicTank on youtube.
He uses a product named aquario neo co2 that is more or less the same as your standard diy co2 systems. Just more expensive and IMO, not worth the cost in the long-run relative to a regulator and a tank.

But the results don't lie, with some intensity tuning on the LED's you can get it in a spot where the co2 is adequate for the system.
 
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