Advice on adding co2 to planted tank needed!

Hello everyone!

I am new to using co2 in the aquarium. I have a few questions. So firstly, I have concerns about the oxygen levels in my tank. I have a drop checker which I am closely monitoring but I worry that even if it doesn't turn yellow my fish may be lacking oxygen. They don't go to the surface gasping for air but they do open and close their mouths kind of frequently? Should the air pump be off when the co2 is on? I just turned the co2 on today. Also, should I be using a powerhead? And if so, where is the best location? Where should my diffuser be? I will be switching to an inline reactor in the next week or so, but I wanted to try and get some co2 in the tank now since my plants seem to be struggling and I had these parts on hand. Is surface agitation bad when you have co2? I want to get a spray bar eventually for my tank but am not sure if it will cause issues with the co2. Forgive me if I sound ignorant, I am trying to figure this out as I go and I don't personally know anyone that has planted tanks to ask for advice. I am trying to ensure that I have good circulation, enough oxygen for my fish while maintaining enough co2 for my plants. Any and all advice/criticism is appreciated! Picture of my tank for reference. TIA!

 

I am new to using co2 in the aquarium. I have a few questions. So firstly, I have concerns about the oxygen levels in my tank. I have a drop checker which I am closely monitoring but I worry that even if it doesn't turn yellow my fish may be lacking oxygen.

CO2 reaching lethal levels is a real possibility in a high-tech tank without enough surface agitation.

They don't go to the surface gasping for air but they do open and close their mouths kind of frequently? Should the air pump be off when the co2 is on? I just turned the co2 on today. Also, should I be using a powerhead?

You'll need some surface agitation to make sure your fishes stay safe. This agitation can come from your air pump, powerheads, or whatever.

And if so, where is the best location?

Typically, the best location is in a top front corner. I know that can be a bit ugly, but you'll want a decent flow that gently swirls around the whole tank leaving as few dead spots as possible.

Where should my diffuser be?

It should be in a place where the bubbles don't rise straight up to the surface. That is, place the diffusor in a spot where the bubbles end up getting caried around by the current.

I will be switching to an inline reactor in the next week or so, but I wanted to try and get some co2 in the tank now since my plants seem to be struggling and I had these parts on hand. Is surface agitation bad when you have co2?

No, surface agitation is good. You will lose more CO2 and have to fill your canisters more often, but you can keep your CO2 at a steady higher level. The provided stability running more CO2 in a tank with good surface agitation and flow will help head off many algae problems, plus it will provide a sort of ceiling to your CO2 levels making sure your fishes are always safe.

I want to get a spray bar eventually for my tank but am not sure if it will cause issues with the co2.

Spray bars are great, don't be afraid to use one.

Forgive me if I sound ignorant, I am trying to figure this out as I go and I don't personally know anyone that has planted tanks to ask for advice. I am trying to ensure that I have good circulation, enough oxygen for my fish while maintaining enough co2 for my plants. Any and all advice/criticism is appreciated! Picture of my tank for reference. TIA!

No problem. Chech out this video on gas exchange and CO2 injection (I think you'll find it helpful):

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CO2 reaching lethal levels is a real possibility in a high-tech tank without enough surface agitation.

You'll need some surface agitation to make sure your fishes stay safe. This agitation can come from your air pump, powerheads, or whatever.

Typically, the best location is in a top front corner. I know that can be a bit ugly, but you'll want a decent flow that gently swirls around the whole tank leaving as few dead spots as possible.

It should be in a place where the bubbles don't rise straight up to the surface. That is, place the diffusor in a spot where the bubbles end up getting caried around by the current.

No, surface agitation is good. You will lose more CO2 and have to fill your canisters more often, but you can keep your CO2 at a steady higher level. The provided stability running more CO2 in a tank with good surface agitation and flow will help head off many algae problems, plus it will provide a sort of ceiling to your CO2 levels making sure your fishes are always safe.

Spray bars are great, don't be afraid to use one.

No problem. Chech out this video on gas exchange and CO2 injection (I think you'll find it helpful):

.

Thank you for all of that information! However you're saying I have to essentially waste co2 in order to make sure fish stay safe? It seems a bit redundant to use more co2 so that I can essentially waste it. I don't mean to sound rude so I apologize if I do. Can I just watch my fish to see if they start to struggle? I've attached a video of their current behavior. I only have a 5 gallon co2 tank and would prefer not to have to refill it more than necessary.

 

Thank you for all of that information! However you're saying I have to essentially waste co2 in order to make sure fish stay safe? It seems a bit redundant to use more co2 so that I can essentially waste it. I don't mean to sound rude so I apologize if I do. Can I just watch my fish to see if they start to struggle? I've attached a video of their current behavior. I only have a 5 gallon co2 tank and would prefer not to have to refill it more than necessary.

Not rude at all. I know it sounds counterintuitive, but, yes, if you want stable CO2 levels without risking killing your fish, you will need to increase surface agitation and inject more CO2. One may see this as wasteful, but I see it as necessary for a stable high-tech tank.

You can try to decrease surface agitation and CO2 injection rates, but it will take like 4-6 hours for the CO2 to get up to optimal levels. So, you'd have to turn the CO2 on much earlier than the lights (You'd still need to turn the CO2 on 2 hours or so before lights on even with a higher injection rate). Also, without sufficient surface agitation, there's always the risk that your CO2 could still build up to lethal levels at the end of the day (I have made this mistake before).

You could turn your CO2 injection down so low that you never risk killing your fishes, but then the CO2 levels will be unstable throughout the day. Unstable CO2 stresses your plants and highly encourages algae to grow.

If you don't want to use extra surface agitation and injected CO2, you're probably better off going with a low-tech tank. A low-tech tank is more stable and won't run into the same problems as a tank with a low CO2 injection rate.

 

Yeah I've been dealing with staghorn algae and my plants are just not looking great. I want to have a heavily planted tank so I will do what it takes to do the co2 properly. Thank you for all of that info and taking the time to explain and answer all of my questions. I very much appreciate it! So with an inline reactor I still need the extra surface agitation correct? And I can just use the air pump to do that? Since I already have the air pump in the tank it seems pointless to add the powerhead, right? Or would the powerhead be better?

 

Yeah I've been dealing with staghorn algae and my plants are just not looking great. I want to have a heavily planted tank so I will do what it takes to do the co2 properly. Thank you for all of that info and taking the time to explain and answer all of my questions. I very much appreciate it! So with an inline reactor I still need the extra surface agitation correct?

Yes, you will still need the surface agitation.

And I can just use the air pump to do that?

Yes.

Since I already have the air pump in the tank it seems pointless to add the powerhead, right? Or would the powerhead be better?

That's tough to say. Personally, I prefer using a powerhead. I find it easier to get optimal flow (plant leaves sway gently in the current) and avoid dead spots. But, if you can achieve these things with the air pump, there's no need for the powerhead.

 

Yes, you will still need the surface agitation.

Yes.

That's tough to say. Personally, I prefer using a powerhead. I find it easier to get optimal flow (plant leaves sway gently in the current) and avoid dead spots. But, if you can achieve these things with the air pump, there's no need for the powerhead.

Okay, and based on my fishes current behavior would you say they're okay? They don't seem to be struggling but when I look at videos of other angels they don't open their mouths so much

 

Okay, and based on my fishes current behavior would you say they're okay? They don't seem to be struggling but when I look at videos of other angels they don't open their mouths so much

Your fishes look fine to me. When they are stressed by too much CO2, they will rise up and begin breathing at the surface.

 

Your fishes look fine to me. When they are stressed by too much CO2, they will rise up and begin breathing at the surface.

That's what I thought, thank you so much!