Optimizing CO2 in 1200L tank

[RickyV]

Hello UKAPS! I have been struggling with GDA(on glass and plants) for a while now and after reading many of your forum discussions I think my problem is low CO2. To remedy this I am trying to reduce CO2 demand by reducing temp from 28C to 25C, and reducing lighting by 40% (lights are 3 WRGB Pro 90 before were set at 100% intensity). I am also turning on CO2 earlier 2 hours before lights, and increasing the injection as much as the fish can handle. Trying to have proper CO2 right at lights on. One thing I would like to check with people here though is my flow since I hear flow is extremely important for proper CO2.

My tank is 244cm x 71cm x 71 cm, around 1200 liters. As you can see my flow is currently what is above I have a 20,000L per hour return pump (probably only 10,000LPH with the height/plumbing) pumping water from those two outlets and water going to the center overflow to be returned to the sump. Is this sufficient? I feel like it is since I see co2 bubbles everywhere pretty evenly, but I want to make sure. I am considering adding some wavemakers if needed. Where would be the best places to add wavemakers to optimize CO2 distribution?

Another thing I want to check is CO2 duration. From what I understand reading this forum, CO2 usage is highest at the beginning of the photoperiod and becomes much lower near the end. If I have an 11 hour photoperiod how early can I shut off CO2? If CO2 demand becomes much less during the last few hours, does that mean I can shut CO2 off during the last few hours? And if CO2 is off and demand is lower, does that mean I should also decrease my lights to something very dim last few hours? I also hear I should run lights very dim for 30 mins before full intensity to wake the plants up.

I currently have two ista max mini CO2 reactors providing CO2 into my return pump, there is still quite a bit of mist since my injection rate is so high, but it sounds like the best CO2 implementation is one with high dissolution (from my reactors) and high mist. I am still planning on getting a much larger cerges style reactor for my tank just to reduce micro bubbles, though in theory wouldn't my plants be negatively affected by having less mist in the tank?

Is there anything else I am missing that could help optimize the CO2 in my tank?

Sincerely,
Ricky

 

[Hanuman]

Hello and welcome to UKASP,

We have yet another monster tank here, nice. How old is the tank?

I have a 20,000L per hour return pump (probably only 10,000LPH with the height/plumbing) pumping water from those two outlets and water going to the center overflow to be returned to the sump. Is this sufficient?

I think so. That's over 10x the tank volume so yeah pretty much sufficient.

I am considering adding some wavemakers if needed. Where would be the best places to add wavemakers to optimize CO2 distribution?

Not sure that would be necessary. It will depend on plants and fish. You could start by adding mutiple drop checkers at different places in the tank and observe their color. It will tell you the deficient spots. But most plants seem to be centered in the tank so you would need to focus on that.

Another thing I want to check is CO2 duration. From what I understand reading this forum, CO2 usage is highest at the beginning of the photoperiod and becomes much lower near the end. If I have an 11 hour photoperiod how early can I shut off CO2? If CO2 demand becomes much less during the last few hours, does that mean I can shut CO2 off during the last few hours? And if CO2 is off and demand is lower, does that mean I should also decrease my lights to something very dim last few hours? I also hear I should run lights very dim for 30 mins before full intensity to wake the plants up.

Seems like a long photoperiod to me. I think you could bring it down a notch. Maybe 8h-10h max? As for CO2 I would say you could shut it off a good hour before lights off. By that time if the Co2 is properly injected to start with the water should already be saturated. You could do a sunset for the last hour if that something you fancy but it's not a requirement really.

I currently have two ista max mini CO2 reactors providing CO2 into my return pump, there is still quite a bit of mist since my injection rate is so high, but it sounds like the best CO2 implementation is one with high dissolution (from my reactors) and high mist. I am still planning on getting a much larger cerges style reactor for my tank just to reduce micro bubbles, though in theory wouldn't my plants be negatively affected by having less mist in the tank?

Considering the size of the tank those ista reactors seem a bit undersized. A Cerges reactor would probably be better suited. As for the CO2 mist that's debatable. Some will say that mist is good. This said my plants grow just fine without the mist so that's that. It's definitely not going to hurt, that's for sure, but I see it as a waste.

 

[RickyV]

How old is the tank?

The tank is a little over 2 years old, but I upgraded to high tech around 6 months ago.

Seems like a long photoperiod to me. I think you could bring it down a notch. Maybe 8h-10h max?

Yeah I was thinking my photoperiod should be reduced but I also really like the long viewing time. Could I maybe replace the first hour and last two hours with a really dim light? That way I still have 11 hours viewing time, but I only have max intensity for 8 hours.

Considering the size of the tank those ista reactors seem a bit undersized. A Cerges reactor would probably be better suited. As for the CO2 mist that's debatable. Some will say that mist is good. This said my plants grow just fine without the mist so that's that. It's definitely not going to hurt, that's for sure, but I see it as a waste.

If there isn't significant difference in plant health without a mist then that does seem ideal. I watched a video from Dennis Wong saying that including a mist means a higher theoretical CO2 without actually increasing the CO2 ppm which seems like it would be really good since I can give my plants much higher CO2 without gassing my fish. At least that's how I interpreted the video. That said though, I do want to be efficient with my CO2 since I run through a 20lb tank every 2 months and it might not be worth wasting CO2 on mist on such a large tank. It would also be nice to enjoy crystal clear water!

 

[MichaelJ]

Hi @RickyV , That is indeed a Texas sized aquarium! Very nice setup! Welcome to UKAPS! 🙂

As for your questions I cant offer much as I am not a CO2 user. @Hanuman got you covered!

How big is your sump btw. ? - keep in mind that the sump goes towards the water volume which should be factored in when dosing nutrients/CO2 etc.

Also, how much and how often do you do water changes in this beast if I may ask?

Cheers,
Michael

 

[RickyV]

Hi @RickyV , That is indeed a Texas sized aquarium! Very nice setup! Welcome to UKAPS! 🙂

lol. Thank you!

The sump is around 280L. I do EI dosing so I am changing 50% once a week.

 

[foxfish]

Nice tank, from the single picture, it looks pretty heathy!

 

[RickyV]

Nice tank, from the single picture, it looks pretty heathy!

Thanks! It's hard to tell from far away, but as you can see in these pictures the plants have some GDA on them. I think it's been getting better, though it's only been a few days since making changes but I'm crossing my fingers.

 

[Hanuman]

The tank is a little over 2 years old, but I upgraded to high tech around 6 months ago

Ok so the tank is pretty much established.

Yeah I was thinking my photoperiod should be reduced but I also really like the long viewing time. Could I maybe replace the first hour and last two hours with a really dim light? That way I still have 11 hours viewing time, but I only have max intensity for 8 hours.

You could do that. Do it gradually though for plants to adapt. Also don't change multiple parameters at the same time, like for example the lighting, the Co2 etc else you will not know which solved your algae issue. I would start by the lights and see how things go for the next couple of weeks, then adapt accordingly.

I watched a video from Dennis Wong saying that including a mist means a higher theoretical CO2 without actually increasing the CO2 ppm which seems like it would be really good since I can give my plants much higher CO2 without gassing my fish. At least that's how I interpreted the video.

Lots of theory. I mean, it's not wrong, but my tanks have no fine mist and I have virtually 0% algae on all of my stem plants and they grow healthy, perfectly fine and fast. So I guess it's all a matter of if you really want to push it a step further. I don't see the need and I rather have a crystal clear water tank than a soda sprite tank. CO2 mist also ends up covering most plants with bubbles by the end of the day. Some people will like to show off this saying how much pearling is going on but a lot of these bubbles are actually CO2 that has adhered to the plants making it look like the plant is pearling mad. I used to have an inline diffuser and I got this pearling effect everyday. Since I am using a CO2 reactor I don't see this anymore although I am injecting more CO2. To me, actual O2 pearling is subtle and it's not a full tank saturated with bubbles on all plants like soap party. Just my experience.

 

[RickyV]

Also don't change multiple parameters at the same time, like for example the lighting, the Co2 etc else you will not know which solved your algae issue. I would start by the lights and see how things go for the next couple of weeks, then adapt accordingly.

Ok will do that and see how tank responds. That makes sense to not change to many things at a time. I was just being impatient and attacking the algae with everything I got lol.

my tanks have no fine mist and I have virtually 0% algae on all of my stem plants and they grow healthy, perfectly fine and fast. So I guess it's all a matter of if you really want to push it a step further. I don't see the need and I rather have a crystal clear water tank than a soda sprite tank.

That is good to hear, I will definitely be getting a bigger reactor.

 

[dw1305]

Hi all,

I watched a video from Dennis Wong saying that including a mist means a higher theoretical CO2 without actually increasing the CO2 ppm

CO2 mist also ends up covering most plants with bubbles by the end of the day.

I'm guessing that is probably the reason for Dennis Wong's comment, it is the bubbles of CO2, in contact with the leaf surface, that maximise CO2 uptake.

To me, actual O2 pearling is subtle and it's not a full tank saturated with bubbles on all plants like soap party.

I think that is right as well. There are plenty of <"pictures of "pearling"> where the bubbles have definitely not come from the plant.

cheers Darrel

 

[JoshP12]

Is there rich substrate? Sorry if I missed it.

 

[RickyV]

Is there rich substrate? Sorry if I missed it.

I use a mixture of pool filter sand with gravel (mostly sand). I try to add root a lot of osmocote under the swords and tiger lotus. I add osmocote tabs under the other plants, but I'm probably not adding enough.

 

[JoshP12]

I use a mixture of pool filter sand with gravel (mostly sand). I try to add root a lot of osmocote under the swords and tiger lotus. I add osmocote tabs under the other plants, but I'm probably not adding enough.

Awesome!

Looks like reducing your light did the trick as I see some updated photos above.

I think you could also go another way: pull back your water column ferts to 6NO3 and 3 PO4 and around 15K. And then turn the light back up. Sounds counterintuitive but i think it would also work.

But if it’s all looking good and the way you want now then that’s what’s most important!!

Cheers,
Josh

 

[RickyV]

Awesome!

Looks like reducing your light did the trick as I see some updated photos above.

I think you could also go another way: pull back your water column ferts to 6NO3 and 3 PO4 and around 15K. And then turn the light back up. Sounds counterintuitive but i think it would also work.

But if it’s all looking good and the way you want now then that’s what’s most important!!

Cheers,
Josh

That does sound counterintuitive lol. Is the idea here that macros control the growth of plants and thus the CO2 demand? This is a very interesting idea! Do you have some forum posts or articles talking about this method? I would like to read more about this.

 

[JoshP12]

That does sound counterintuitive lol. Is the idea here that macros control the growth of plants and thus the CO2 demand? This is a very interesting idea! Do you have some forum posts or articles talking about this method? I would like to read more about this.

That is exactly right. So you bottleneck the co2 demand (that is forced by the light) and let the plant adapt (in color/shape) to control the light. They look prettier in my opinion under this situation. Sometimes the leaves become thinner, more elegant and they "dance" differently ... 🙂.

According to @John q , Goat Leggings are the key.

That's my journal.

That was an older stream of thought.

And then somewhere in there I will probably go on about light and nutrients lol.

 

[RickyV]

Thanks! Will check them out.