CO2 Distribution

[ncsuben]

I’m planning out how best to distribute CO2 in a 75G tank build. I’ve read a lot but also some conflicting information.

The tank will start at least with two large sponge filters, one in each corner, from aquarium coop that have a tube which releases bubbles/O2 toward the surface of the water. In my mind if I direct the outflows in the same direction (say clockwise) this will create some amount of flow throughout the tan, but likely not enough.

I’m going with pressurized CO2 straight from a tank via regulator through a diffuser. Should I run two manifolds to two diffusers spaced evenly on the back of the tank to encourage uniform distribution? OR 1 diffuser placed somewhat centrally with a power head to push the gas through the tank? Then if I run a power head do I use some form of directional flow and perhaps add a second say 12 in away to continue a current? This is where I want to be careful and have enough flow to distribute and not interfere with “low-flow” fish.

I’ve read about splash bars and some who say they help and others who say avoid them. In my mind it would make sense that if there is substantial surface agitation then it would encourage more gas exchange and dissipation of CO2 out of the tank.

Regarding gas exchange, I am going to use glass lids because…cats. And if you think “Oh cats learn their lesson”….this one doesn’t, still attacking the puppy now 3 times his size. Anyway, my thought is to use the glass but not attach the plastic toward the back to have at least 2 or so inches open for gas exchange…if I get fish notorious for jumping ill DIY some form of screen back there.

I know many use CO2 reactors but I can’t have a CO2 tank anywhere near where little hands can access, so I feel like CO2 via 5# (could maybe fit 10#) canister via direct diffusion is my best current option.

Thanks so much for the help!

 

[Pepere]

I wasnever thrilled with diffusers in my tank. I found it difficult to keep the bubbles in suspension. Pretty much they rose straight to the surface, popped and we t away…. I had a canister filter with a spray bar below water surface aimed to front glass that circulated water across top, down front glass , over substrate to back and up. The diffuser was on sidewall and largely out of direct flow.

I tried wavemakers to keep bubbles in suspension and they certainly were not beauty marks, and a major pain having to be cleaned of vegetation daily..

I pulled the diffusers and wavemakers and installed an inline diffuser in the outflow tube that gets distributed by the spray bar..When the CO2 is running you can see the bubbles entrained in the circular flow in the tank.

Sponge filters certainly have the advantage of low cost, but they are no exactly unobtrusive or attractive, and a pain to pull out for cleaning without making a mess…. The Easy flow kits do add a lot of flow… for a sponge filter…

If your goal is for a lush planted tank with vibrant growth and CO2, you might want to give some thought to an appropriately sized canister filter.

 

[Mr.Shenanagins]

I’m going to second this. Sponge filters are great when you’re just dealing with fish. Adding plants to the mix will clog them much quicker, and you’re also now having to add some form of flow to compensate. They also take up real estate in the tank, something precious when your trying to stuff every plant you like in the tank!

IMO as mentioned, canister filters are usually the way to go. You don’t have to break the bank either, plenty of second hand available locally or on eBay. Black Friday sales will also get you a nice new one for a better price than usual

 

[Yugang]

I’m going with pressurized CO2 straight from a tank via regulator through a diffuser.

I may misunderstand your plan, are you saying here that you do have a CO2 cylinder?

I can’t have a CO2 tank anywhere near where little hands can access

Again, sorry if I misunderstood - why not place your CO2 cylinder in a safe spot, and use CO2 tubing to your tank?

 

[Unexpected]

I would highly encourage you to go with a 10lb tank. It's cheaper to purchase, and cheaper to refill. You'll also have less refills per year saving you drive time.

The dilemma, a 75 gallon is the upper range with diffusers and inline diffusers. Meaning, you really have to push CO2 and have really good flow to distribute the CO2. I would highly recommend a reactor. There are several types, but the one I recommend, especially for beginners, is a @Yugang reactor. Why? Because it's the safest reactor design available. I'll explain how it's so safe in the video I'll upload. If you went with a canister filter, you could run the reactor with the canister filter. Just make sure it is a more powerful option to account for some extra head pressure.

 

[ncsuben]

@Pepere @Yugang @Mr.Shenanagins @Unexpected

Thank you all for your input!

So 1: the tank. I would prefer a 10#. I have no clue why it’s so hard in my area to find one at a reasonable price. We have an Airgas but they only exchange. I found a scuba supply that will fill a 5# for $20 and a 10lb for $30. The local homebrew store fills for $50 and $80 respectively. As to who I can actually purchase a 10# from I have yet to discover. Regarding a safe place, I’d love to tuck it in the stand’s cabinet which limits me to 23.5” vertically so unsure where tank + regulator would put me with a 10, but maybe it’ll fit. I don’t want to run tubing from a different room to the the tank (only other option).

I’ve watched/read some things regarding the Yugang reactor and will revisit. I know I could make it, but I was thinking sponge maaaayyyyybe HOB at the time. So I’ll dig in and thanks for e video!

So this now brings up a topic I’m sure is also hotly debated. I don’t want to break the bank, but I’d love something that will last and that I won’t have to worry too much over….so which canister for a 75 do y’all recommend? If I’m going to do this right, let’s try and do it right the first time I suppose!

 

[Unexpected]

GANCOWISE 10lb Aluminum New CO2 Tank, DOT Approved Gas Cylinder with CGA 320 Valve for Kegerators and Draft Beer Dispensing Amazon.com

But check out eBay for old used ones and then just swap it for a full one.

Ehm Fltr 2217 Classic Wm 264g Amazon.com
This filter is a beast. Would easily run the reactor and has a spray bar. But hefty price. Buy once, cry once?

But running an inline pump for the reactor is pretty cheap and then have the HOB or sponge filters.
SICCE Syncra Silent 1.5 Multifunction 357 GPH Submersible Water Pump | Italian Made 23W Ultra Quiet Durable Aquarium Fish Tank, Fountain, Pond, Hydroponics, Terrarium Black | Freshwater & Saltwater https://a.co/d/4AJ2H9X

 

[Koan]

I don’t want to break the bank, but I’d love something that will last and that I won’t have to worry too much over

Not having to worry about your filter is what the Oase Biomaster Thermo is all about:

1) built-in heater, means no ugly heater in your tank

2) built-in pre-filter, means no having to disassemble the damn thing to get gunk out of the bottom more than once or twice a year. The pre-filter sponge catches most of the gunk and is designed to be easily pulled out washed and stuck back in.





3) when you do have to take it apart, it's designed to be modular.


Remember a filter is just a pump in a bucket. A dirty bucket of gunk circulating gunk through your tank is a guarantee for algae and pain.

You want your filter to be as painless to maintain as possible, or trust me you will not maintain it, and you will be sad. Ask me how I know

 

[ncsuben]

Not having to worry about your filter

My apologies, I didn’t complete my thought there. I more meant not having to worry about upgrading…but perhaps this was a fortunate accident as I was unaware of such features in a canister. Thanks!

 

[Koan]

I was unaware of such features

Very frequently go on sale somewhere for Black Friday, keep an eye out at Amazon, Chewy, Walmart, Petsmart , even Tractor Supply this next week.

Note that Oase makes a version with, and a version without, the heater, so make sure you pick up one with the word Thermo in the name

 

[ncsuben]

Oase makes a version with, and a version without, the heater,

You know, I must say I’m always apprehensive with the concept of “all in one’s”. Kind of like our minivan can adjust cruise control according to the speed of the car in front…I don’t really want that as it’s just something else to break.

I’ve got 2 200 watt Eheim Jagers I’ll prob run in the tank. Thanks again for the option though! I’ll prob look into the models without thermo.

 

[Koan]

You know, I must say I’m always apprehensive with the concept of “all in one’s

The heater is removable and replaceable.

 

[Kwyet]

It is, but I have a couple of those and I have trouble priming them. I’ve replaced the priming part a few times too. I’ve decided that unless I absolutely have to have a heater and it needs to stay out of sight, they’re more trouble than they’re worth, and they’re not that powerful either. I saw that you’ve already decided to go with Eheim, but figured I would put my 2 cents in, lol.

 

[ncsuben]

@Kwyet
I appreciate the input! I haven’t gone with any particular canister yet. I’ve got Eheim heaters so was just saying I wouldn’t need the heating component within the canister itself. Happy to hear your experience with any particular canisters.

 

[Kwyet]

I have a Fluval 407 on my 125 gallon, along with the above mentioned Biomaster Thermo. It’s never given me any trouble. I think the fittings it comes with are ugly, so I’ve replaced them with stainless steel and regular hoses. I have a Fluval Fx4 on my 68 gallon, which replaced a Biomaster 600 thermo. It’s a lot more powerful. The drawback with that one is that it has a 1-inch inlet and outlet, so I had to replace the lily pipes, hoses, and reactor that I was using. I have Oase filtosmarts on much smaller tanks, and they work fine. No experience with Eheim, but I know a lot of people love them.

 

[Pepere]

If a canister filter is a bit of a stretch budget wise initially, you could opt for an Under Gravel filter.

Amazon sells one for a 55 gallon tank that would be perfectly adequate in a 75. It features 4 uplift tubes.




It is easy enough to make adapters to fit Co Op Easy flow kits for increased flow if you prefer air driven filtration. Alternatively you could plumb up a power head and have that powerhead feed into a co2 reactor or a spray bar under the water surface…. An Undergravel Filter provides comparable amount of biofiltration as a canister filter, and with a powerhead comparable flow. It does however lack the mechanical filtration and the ability to utilize chemical filtration.

One could always add a canister at a later date.

I like to run UGF filters on my tank as cheap back up. In the event of a power outage, where I am not present, that lasts over an hour or more, the beneficial bacteria in the canister filter might well be compromised.. the UGF establishes a good beneficial bacteria colony in the gravel. Even without flow, the beneficial bacteria in the gravel will have access to far more oxygen than within the canister filter and likely to survive longer without flow. Once electricity is re established the cNister filter can be well cleaned and put into service and the UGF can provide biofiltration until colony re establishes in the canister.

I use a Unicliffe air pump with variable power output that can drive the filtration with about 2 watts of power when dialed down.

I place mesh bags of Safe T Sorb which is a fired clay product with high Cation Exchange Capacity filled about 3/4 of an inch directly on the plates and a 2 inch cap of BDBS on top.

My thoughts, which I freely admit to not having data is valid, is that the continual flow of water column fertilization through the substrate via the UGF provides nutrients to the safe t sorb. When placing plants in the BDBS the roots are in close proximity to the Safe TSorb and they readily intrude into it. The mesh bags prevent the Safe T Sorb from coming up with the roots when you uproot them. The Mesh bags of the Safe T Sorb also prevents the BDBS from filling up under the UGF plates.

Recently I tore down a tank that had this set up to reset it after I had a bag of Purigen split a seam in my canister filter creating a purigen snow storm in the tank. I found the bags full of root hairs and no roots under the UGF plates. The plant roots seemed quite at home in the mesh bags…

I fully realize I am an outlier in thus method and perhaps thought a bit eccentric, but it seems to work well for me.. In any event it is incredibly cheap, versatile and if one decides not to utilize it after a while it is as simple as removing the air risers to discontinue use…

It is worth consideration.




Here you can see I run a canister filter in addition with a skimming intake and a spray bar.

 

[ncsuben]

@Pepere that is fascinating and a new one for me. Very interesting approach.

I’m going to hunt around Black Friday deals here and there. Apparently I missed a sale on the Eheim 2217 at bulk reef supply….though their base price pre sale seemed lower than others with it on sale. Makes me wonder if it’s truly a new non-refurb product.

Anyway, this is an excellent alternative that has more than piqued my curiosity.

 

[Art]

Well, I have a lot of thoughts and suggestions here. I think others have touched on many key points for you to consider.

When my kids were little, I always felt uneasy with my CO2 tank in the house. If you’ve had young kids, you know they can get into everything and anything. So, if this sounds like yours, I would suggest securing the tank to the side of the inside of your cabinet.


Something like this to the left is what I would recommend. You can easily find them online for less than $20. Peace of mind with kids is critical. If I’m blessed with grandkids someday, I’m going back to these.

On filters for your 75, I would recommend a canister filter as probably being your best bet. The Eheims are workhorses that will last forever and are quiet. The Oase have solved an important downside of traditional canisters, how to easily rinse out the mechanical filter that should be rinsed every week or so.

I advise to always keep heaters separated and to use two instead of one. I also consider heaters disposable 1 year items. So I would recommend two smaller ones instead of one and buy the best quality you can afford.

People are also using external temp controllers that have heating elements inside the tank. This is also a good option as usually the heating element will last longer than the traditional all in one heater.

Regarding the CO2 distribution, what you are aiming for is for the CO2 laden water to be circulated around your aquarium as best as you can. CO2 diffused in water (happens very quickly) will spread throughout the water column well. That is not hard to do given how water diffusion works. The reason you want water flow to reach all parts of your aquarium is to cause some level of flow across all plant surfaces. Of course, detritus accumulation and filter pattern are other reasons.

On plant surfaces, a boundary forms between the plant and the water. “A "boundary layer" between an aquatic plant surface and water refers to a thin layer of water immediately surrounding the plant's surface, where the water flow is significantly slower compared to the bulk water movement, creating a zone of reduced water movement that can affect gas exchange and nutrient uptake for the plant; essentially, it's the interface between the plant's surface and the surrounding water, influenced by the plant's surface texture and the water flow conditions.”

We need to disrupt this layer so the plant can better take in CO2 and also expel substances it needs to. At the same time, we need to make sure that we provide a good environment for the fish and not cause plants to be blasted too strongly.

I have found that several methods achieve the above best, at least for me. One is an inline CO2 diffuser on the return of you canister filter. The return should be into a Lily Pipe or similar that will provide a good current all around your aquarium. The other are CO2 diffuser(s) on one side of the aquarium with a gyre type pump on the other that flows a stream of water over the surface of your aquarium, down the opposite side with the diffuser and then back across the bottom of the aquarium. Something similar can be achieved with spray bars.

Just some food for thought for you.

 

[Pepere]

When my kids were little, I always felt uneasy with my CO2 tank in the house. If you’ve had young kids, you know they can get into everything and anything. So, if this sounds like yours, I would suggest securing the tank to the side of the inside of your cabinet.

You had mentioned wanting a 10 lb tank due to space limitations in cabinet. 10 lbs is a much less frequently utilized size. My local gas shop keeps 5lb tanks and 20 lbs tanks in stock for swapping. The cost of a 20 lb swap is only about $15.00 more than the cost of a 5 lb swap, $45.00 for the 5 lb, $60.00 for the 20 lb. since the labor to fill it and pressure test the tank as needed, and maintain the tank is the same. Ie with a swap, the store is taking on all the compliance regulations…

So for a fractional increase in cost, I swap out tanks twice a year vs 8-9 times a year.

If you have any sort of woodworking skills a cabinet can be made to house the cylinder and enclose the controls from curious hands and minds…. Little more than a box with a door…

I build my own tank stands using knotty pine toungue and groove beadboard. Easy enough to make one tall enough to accomodate a 20 pounder.. I certainly trust dimension lumber fir a self built stand much more than the glue and sawdust panels store bought stands are constructed from.

 

[Pepere]

@ncsuben , here is a link showing how I make simple adapters to fit easy flow kits to Penn Plax UGF plate risers.

Making adapters to retrofit Easy Flow kits to my Under Gravel Filter Plates.

I thought some people might like to see how I retrofitted some Easy Flow kits to my UGF plates. The first step was going to the hardware store to find some fittings that might work. These 3/4 threaded adapter will fit just fine once the threads are filed down.. The air riser tube from the UGF is ...

forum.aquariumcoop.com

One could adapt the same idea to plumb in a powerhead to them.