Should I add co2 to existing aquascape

[Kave_art_man]

Ok here’s where I’m at

I’ve had my scape going now for just under a year, in that time I’ve changed a lot of things, added tonnes of more plants.
Setup is an oase styline 125 with an oase thermo 200 for filtration and no co2

So I’m thinking to add co2 to this tank, just wanted to get your ideas on weather it’s a good idea or not.
Have any of you added co2 to scape that’s been going for while without it already?
How will the fish cope? It’s a heavily stocked tank
Would it be better to just do a little bit of co2 to boost the plants a bit or go for the full 1 drop on ph for when the lights come on?
Got some algae problems constantly, will the co2 make it worse, give need problems or help in the issues?

Should I just do a rescape of the tank totally and start a new with co2?

Thanks a lot with whatever advice you can provide. I will say haven’t done co2 yet but brought the regulator during Black Friday as I knew sooner or later I would want one and the deal was too good to turn down

 

[ScareCrow]

This is something I'm also considering. From the reading I've done:

• If you already have algae, CO² will make it worse so you need to get on top of that first.
• The ideal situation is to get CO² set before adding fish as it's safer but can still be done as long as it's done carefully.

It might help to put up a pic of the tank and show how flow is distributed around the tank. A lot of CO² issues I've read about seem to come from poor distribution.

 

[Nick potts]

Ok here’s where I’m at

I’ve had my scape going now for just under a year, in that time I’ve changed a lot of things, added tonnes of more plants.
Setup is an oase styline 125 with an oase thermo 200 for filtration and no co2

So I’m thinking to add co2 to this tank, just wanted to get your ideas on weather it’s a good idea or not.

CO2 is always a good idea for the plants, they may not absolutely need it but all plants benefit from CO2

Have any of you added co2 to scape that’s been going for while without it already?
How will the fish cope? It’s a heavily stocked tank

Just start slow and gradually adjust the CO2, the fish will be fine as long as you take it slow.

Would it be better to just do a little bit of co2 to boost the plants a bit or go for the full 1 drop on ph for when the lights come on?
Got some algae problems constantly, will the co2 make it worse, give need problems or help in the issues?

I'd just go all out and aim for the 30ppm.

If you already have algae, CO² will make it worse so you need to get on top of that first.

Not heard this before.

 

[ScareCrow]

CO2 is always a good idea for the plants, they may not absolutely need it but all plants benefit from CO2

Just start slow and gradually adjust the CO2, the fish will be fine as long as you take it slow.

I'd just go all out and aim for the 30ppm.

Not heard this before.

For some reason I jumped to filamentous algae but the same will be true for most photosynthetic algae. Unless the 'desired' plants can outcompete the algae, the growth rate of the algae will be increased by the addition of CO². Maybe if the algae is caused by too high a light intensity or too long a duration the addition of CO² might help balance things but I'm never that lucky . I'd sooner try and work from a 'known good point'.

 

[Tim Harrison]

Yes you can add CO2 to an existing low-energy scape. Plants will definitely benefit even if you just add enough to turn the drop checker green rather than lime green.
Since the tank is already carrying livestock it'd be best to increase CO2 gradually over a week or so to acclimatise them; keep a watchful eye out for any signs of stress.

Adding CO2 will almost certainly not make any existing algae worse, But optimizing flow and distribution of CO2 is always key.

 

[John q]

Have any of you added co2 to scape that’s been going for while without it already?
How will the fish cope? It’s a heavily stocked tank

I've added Co2 in two tanks that were both established low tech tanks, they were also well stocked with fish.
Biggest difference i noticed was the increase (speed) in plant growth, which can be a blessing and a curse. Overall plant health also increased.

The fish didn't have any issues adapting to life with gas injection, but I took things slowly, I also did the change over an extended bank holiday weekend, so had 4 days to watch and monitor the ph drop.
I see no reason not to aim for the full 1 point drop, providing it doesn't stress the fish.

I also waited about 4 weeks before I even thought about increasing the light intensity, and when I did it was increased slowly, even today my lighting would be considered low by most.

I think a lot of people run into issues when converting from low tech to high tech because they assume the tanks can instantaneously be blasted with light, this would likely be the cause of many of their issues.

You've also got to consider any potential flow issues and maintenance schedules. In low tech set ups we are allowed a certain amount of leeway here, with high tech any faults or laziness soon gets punished.

So I'd say go for it if you've got the urge, just do it slowly and appreciate it may require more effort than low tech.

 

[ScareCrow]

Adding CO2 will almost certainly not make any existing algae worse

Fair enough, I stand corrected, apologies @Nick potts and Kave_art_man. I don't understand how it will not increase the rate of algae growth though. If CO² will increase the rate of plant growth why not algae too (unless the cause of algae is light duration/intensity)?

 

[Tim Harrison]

It's not necessarily a linear equation. You are right light intensity and duration play a role. CO2 should increase the competitive advantage of higher plants provided light intensity and duration remain in balance with CO2 flow and distribution.

 

[arcturus]

Fair enough, I stand corrected, apologies @Nick potts and Kave_art_man. I don't understand how it will not increase the rate of algae growth though. If CO² will increase the rate of plant growth why not algae too (unless the cause of algae is light duration/intensity)?

This is an excellent question that I believe has no simple answer. You will find plenty of literature discussing this topic and many open questions.

If you dump nutrients in a waterway that gets plenty of light, the resulting eutrophication process can trigger a major algae outbreak. So, it seems a paradox that you can add nutrients in excess (such as with the EI method) along with lots of light and CO2 to a planted tank and still have healthy plants instead of a huge mass of algae, because there will be no limiting factors for algae growth.

Different algae and bacteria types will always be present in any tank at any moment. In a healthy tank they will grow in the hardscape and glass, but seldom over the plants. The question is if the current balance of the system is promoting the growth of algae or the growth of higher plants. If the mass of higher plants is sufficient and is healthy (which means it will be more resilient to algae and other organisms), then the system tends to promote the growth of higher plants because of several complex interconnected factors that are still the focus of research. For example, a large plant mass can reduce the light available to algae; a large healthy plant mass leaves less surface for algae; healthy plants release less organic materials into the water column that might trigger algae growth; some healthy plants might release <allelopathic substances> that can stunt the growth algae (as well as the growth of other plants) - this latter point is a well-known fact in terrestrial plants but is quite controversial in aquatic plants. Anyway, this is similar to the balance you find in a mature forest. The trees, plants and undergrowth are all in balance. It is not possible for the undergrowth and plants to start growing wild if the rest of the system remains in balance. But if a couple of trees are cleared out, the undergrowth and plants will take advantage of the small change in the system, often at an extremely fast rate.

In a "high tech" tank, algae easily appear as soon as the system is tipped out of balance because there are few limiting factors. You can easily trigger a small algae outbreak if you let decomposing matter in the tank. An unhealthy plant will also get covered by algae quite fast. If you leave CO2 off for a couple of days you can trigger a significant amount of algae. If you keep CO2 off for a week you risk a massive algae outbreak. But these problems are rather easy to identify. The real long-term problems derive from an imbalance or instability of nutrients, CO2, and light, because these create havoc with the higher plants and tip the system towards algae growth. Worse, this imbalance can still exist even if nutrients and CO2 seem to be provided in "adequate" amounts but it they are poorly distributed, which is often the case with CO2 injection.

Moreover, I believe that regular maintenance (large water changes, plant trimming, debris removal, etc.) must increase as the limiting factors are reduced. I seriously doubt that you can keep a high-tech tank stable for long with reduced maintenance. IMO, the balance of CO2, nutrients, light is a necessary condition for stability but it is not sufficient in a setup with very few limiting factors. Maintenance is what is keeping the algae in check (i.e. less visible). In contrast, a balanced Walstadt/nature tank is stable because is designed around limiting factors.

TL;DR: if a large mass of higher plants are healthy, if CO2, nutrients, light are consistently provided and balanced, if the tank is carefully maintained, then the system will promote the growth of higher plants instead of algae.

 

[Tim Harrison]

TL;DR: if a large mass of higher plants are healthy, if CO2, nutrients, light are consistently provided and balanced, if the tank is carefully maintained, then the system will promote the growth of higher plants instead of algae.

I think that pretty well sums it up. There are numerous posts which explore similar ground. However, there is one missing ingredient which is often fundamental to a healthy and thriving planted tank and that is plant density.

High plant biomass encourages stability. Mature tanks with dense planting can become unbelievably robust. So much so that they are often self sustaining with minimum maintenance. I've had several tanks that have gone months with just top ups. Obviously the other variables such as CO2 conc. and fertz have remained constant.

 

[Kave_art_man]

This is why I love this forum, the power of group mind is strong
Thank you for all your relays
I got another question- with the oase style line would you consider the lights low medium or high, I’ve got two running, there’s room for 2 more - I think they would be in the low to medium category but just wanted to get your views

 

[arcturus]

This is why I love this forum, the power of group mind is strong
Thank you for all your relays
I got another question- with the oase style line would you consider the lights low medium or high, I’ve got two running, there’s room for 2 more - I think they would be in the low to medium category but just wanted to get your views

You would need a PAR light sensor to answer to that question. According to <Oase StyleLine 125> specs, it seems the set includes 2 x HighLine Classic LED Daylight 60 (600mm length) - but you need to confirm if this is correct. If yes, you would have a total output of 2 x 1300 lumen = 2600 lm. The StyleLine 125 has a max volume of ~125 litres, which means you should have something like 100-115 litres of water, depending on your scape. So, for 100-115 litres you have a theoretical maximum light flux of 26-22 lm/l.

Several generic lighting guidelines (e.g., Daytime, Tropica) classify lighting as "medium" (whatever that means) when you have 20-40 lm/l. So, with 22-26 lm/l your lights are in the bottom bracket of the medium category.

Now, you need to take these numbers with a massive grain of salt. For instance, the lumen/litre ratio ignores several key variables including the height of the tank, how the light fixture is actually distributing light, as well as the light spectrum of the LEDs. So, this ratio is just a guideline since it does not tell you at all how much energy is actually available for the plants to photosynthesize. You would need a PAR meter to measure the available light at different locations inside the tank.

The good news is that you can ignore all of the above and just observe if your plants are growing healthy Start with ~5h of light, consistently provide sufficient ferts, keep the CO2 levels as stable as possible throughout the whole photo-period, and keep up with regular maintenance. Also note that your tank has a height of 50cm, which is significant. So, in the future you might consider an extra light bar (or to replace one of the existing bars) to facilitate light distribution, especially if you have some demanding bottom/carpet plants. But with more light you then need to make sure you are providing sufficient CO2 and ferts. But I would keep the original lights for several months until the system is running stable with the CO2. Do not add more lights and CO2 injection at the same time... that is asking for trouble.

In short, ignore the lumens and light categories, because the plants will tell you if they are happy or not.

 

[barnzy101]

You would need a PAR light sensor to answer to that question. According to <Oase StyleLine 125> specs, it seems the set includes 2 x HighLine Classic LED Daylight 60 (600mm length) - but you need to confirm if this is correct. If yes, you would have a total output of 2 x 1300 lumen = 2600 lm. The StyleLine 125 has a max volume of ~125 litres, which means you should have something like 100-115 litres of water, depending on your scape. So, for 100-115 litres you have a theoretical maximum light flux of 26-22 lm/l.
View attachment 178495
Several generic lighting guidelines (e.g., Daytime, Tropica) classify lighting as "medium" (whatever that means) when you have 20-40 lm/l. So, with 22-26 lm/l your lights are in the bottom bracket of the medium category.
View attachment 178496

Now, you need to take these numbers with a massive grain of salt. For instance, the lumen/litre ratio ignores several key variables including the height of the tank, how the light fixture is actually distributing light, as well as the light spectrum of the LEDs. So, this ratio is just a guideline since it does not tell you at all how much energy is actually available for the plants to photosynthesize. You would need a PAR meter to measure the available light at different locations inside the tank.

The good news is that you can ignore all of the above and just observe if your plants are growing healthy Start with ~5h of light, consistently provide sufficient ferts, keep the CO2 levels as stable as possible throughout the whole photo-period, and keep up with regular maintenance. Also note that your tank has a height of 50cm, which is significant. So, in the future you might consider an extra light bar (or to replace one of the existing bars) to facilitate light distribution, especially if you have some demanding bottom/carpet plants. But with more light you then need to make sure you are providing sufficient CO2 and ferts. But I would keep the original lights for several months until the system is running stable with the CO2. Do not add more lights and CO2 injection at the same time... that is asking for trouble.

In short, ignore the lumens and light categories, because the plants will tell you if they are happy or not.

This has been a really interesting read.
I've got an Oase styleline 125 as well and I've tried all sorts with the lights to try get the right amount of light to help keep my tank balanced.
I've got it quite heavily planted at the minute and I'm just using the back light for 4 hours in the morning and the front light for 4 hours in the afternoon as the lights seemed to bright when on together so I tried cutting down the brightness but not the time.
This has now even given me algae on my sand which I've not had before.
So really these light should be fine to have both on at the same time but for a shorter period rather than less light for a longer period?
I've always wonder if because the lights are built into the tank they are too close to the surface of the water.
What would your thoughts be on this?

 

[dw1305]

Hi all,
Welcome to UKAPs

I've got it quite heavily planted at the minute

Can we have a picture? It is just going to make things a lot easier for us.

cheers Darrel

 

[barnzy101]

This is how my tank looks at the minute! I’ve cut a lot of the plants at the front down as the leaves had gone a bit bad and had algae on.
I’ve not got a huge amount of fish in there so it’s not over stocked and I’m running a biomaster 250 filter on it as well.
Any comments will be much appreciated.

 

[dw1305]

Hi all,
That doesn't look too bad at all, but I'd describe it as "lightly planted".

I’ve cut a lot of the plants at the front down as the leaves had gone a bit bad and had algae on.

Personally I'd remove any yellow leaves, or leaves that have started to go rotten at the base, but I wouldn't remove a good green leaf just because it has algae on it.

I know it is difficult, but you need to <"look past the algae"> and concentrate on the plants, on keeping them healthy and building up the plant biomass.

I like a floating plant, either as a sub-surface floater <"Using stem plants as a filtering aid at Start Up!"> & <"C02 ISSUES"> or as a obligate floating plant <"What is the “Duckweed Index” all about?">.

cheers Darrel

 

[barnzy101]

Hi Darrel

Thanks for your feed back, That's quite reassuring to hear then as obviously I'm still fairly new to this and still experimenting.
I'll look to add some more plants then, I have looked at floating plants before but never given them a try as my tank has a sliding top so its enclosed and the bulbs are only a few mm away from the surface of the water so I figured they would be to close to the lights.

So going back to my original question, do you think I should be able to have both the light bulbs on this tank running at the same time rather than having only one on at a time?
I always imagined that as its sold as a set with the two bulbs it is designed to have them both running but it just seem a bit much from my experience.

 

[dw1305]

Hi all,

So going back to my original question, do you think I should be able to have both the light bulbs on this tank running at the same time rather than having only one on at a time?

I would have both on. I always run my lights at "full" <"for ~12 hours a day">, even when they are dimmable. It just takes <"lack of PAR"> out of the equation.

cheers Darrel