Providing 'just enough' CO2

[foxfish]

From my own experiences of trying to use just a little bit of extra C02 it did not work very well long term.
The problem is, it starts off ok but, then the plants grow and require more C02 so you need to either remove the plants or increase the gas or watch the algae grow!
Based only my own short tries and experience you understand.....

 

[tiger15]

From my own experiences of trying to use just a little bit of extra C02 it did not work very well long term.
The problem is, it starts off ok but, then the plants grow and require more C02 so you need to either remove the plants or increase the gas or watch the algae grow!
Based only my own short tries and experience you understand.....

It also depends on the plants you grow. I grow only low light easy plants in medium light that thrive even without CO2, so some CO2 is a quantum boost. I used up one 10 lb CO2 in a year. But I read other aquarists who grow Ductch stems in high light used up 10 lb CO2 in 3 months for the similar size tanks.

 

[AverageWhiteBloke]

The problem is, it starts off ok but, then the plants grow and require more C02

The reason I ended up in this post was because I'm in a similar position as @Courtneybst I've been running lowtech very easy plants for a while without issue but I've got adventurous and tried a few stems coupled with higher plant mass and a couple of medium plants which are starting to show co2 is in short supply so it's taking a bit of balancing.
Many times over the last few weeks I've reached for the numerous co2 equipment at my disposal but I know it's just not going to end well. Before I know where I'm at I'll be looking to improve flow, adding more equipment and just generally fussing about ferts in an ever changing environment. Before I know where I'm at I'll be too busy watching the bubble counter to even see the tank
Plus, considering 90% of the co2 getting pumped just ends up in the atmosphere it's not like the planet could do with another co2 user.
I wonder though if a simple bell arrangement just letting the co2 absorb into the column passively might yield better results than atomizer and diffusers etc in a low light easy plant situation?

 

[sparkyweasel]

I wonder who and why it is necessary to set 30 ppm as the goal.

I think it was originally intended to be a maximum, as most fish can tolerate that level. Then it got misinterpreted as a goal.

 

[AverageWhiteBloke]

think it was originally intended to be a maximum

Yeah that's how I always understood it, 30 was the point fish became uncomfortable.

 

[tiger15]

I think it was originally intended to be a maximum, as most fish can tolerate that level. Then it got misinterpreted as a goal.

It is not common misinterpretation. It is codified in the 1 pH drop goal, drop checker color chart, and CO2 calculator.

Rotala Butterfly | Planted Aquarium CO2 Calculator

Planted Aquarium CO2 Calculator

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[AverageWhiteBloke]

It is not common misinterpretation. It is codified in the 1 pH drop goal,

I think that's why we need forums like these to clarify the many conflicting theories out there, there should certainly be some caveats to many of the articles we come across. I think a lot of it comes down to each persons individual goals. There's a broad range of options but the problem is when most first get into the hobby it seems very black and white until you dig a bit deeper and actually learn about the plants themselves. Most will gravitate towards the high tech stuff straight from the off because these tend to contain the most eye candy. This inevitably steers them down a path of unlimited nutrient dosing and high co2 values which unless they read a bit further into it and find out why these values are necessary they will just accept as the norm.

You come across this many times in the hobby on all topics, commercial fertiliser companies are still claiming N and P cause algae, you also tend to find n and p are very weak in their mixes but they are trying to sell ferts so the more you use the better it is for them and they always advise you to use more "depending on the amount of plants" EI dosing is likely far too much fertiliser for most mere mortals in here but it is applied as a belt and braces non limiting approach. Generally speaking when you buy a commercial DC the colour indicator chart will say "too much" co2 when it gets a bit yellow but high tech people will aim for this. All needs caveats.

This thread finds itself smack bang in the middle of the two methods of growing plants, I would suggest that adding some co2 will certainly help to keep healthy plants as not having enough is as complicated as having high values but this is dependant on many other factors like flow, types of plants were are trying to grow and the lighting being used. The co2 element of planted tanks is certainly the most complicated. It's all down to what the person who is creating the tanks goals and expectations are I guess.

IME, once someone sets off down the path of injecting co2 it inevitably starts off a chain of events that will lead you to 30ppm levels, increased fert dosing, looking for better lighting, more trimming and bigger filters. Once plants have had a taste of co2 it's very difficult if at all possible to go back without destroying the tank. Very much so an in for a penny in for pound scenario. Pretty standard stuff in that world, meanwhile I'll head back over to the low tech section and try and work out why my plants aren't growing fast enough or are losing leaves. It's a great hobby Luckily we have some very clever people here who can explain why....in their own words

 

[Courtneybst]

most mere mortals

love it.

But honestly the rest of your comment, very well put. That's definitely made me think.

 

[Zeus.]

Any level ([CO2]) above 'normal' the plants will benefit from as long as you don't exceed the max for your livestock.

However, many folk injecting CO2 have issues which are CO2 related, whilst folk not using CO2 dont have CO2 issues. Implementation of CO2 injection is tricky and what ever level of CO2 you aim for it needs to be stable for main part of photo period.

 

[Courtneybst]

I hope in 20 years time we'll laugh at these posts trying to use pressurised canisters for CO2 injection and instead there'll be a little contraption that just pulls in CO2 from the air into your tank!

 

[Zeus.]

I hope in 20 years time we'll laugh at these posts trying to use pressurised canisters for CO2 injection and instead there'll be a little contraption that just pulls in CO2 from the air into your tank!

Well, 'they' are trying to find one to save the planet from increasing CO2 levels

 

[Kezzab]

IME, once someone sets off down the path of injecting co2 it inevitably starts off a chain of events that will lead you to 30ppm levels, increased fert dosing, looking for better lighting, more trimming and bigger filters. Once plants have had a taste of co2 it's very difficult if at all possible to go back without destroying the tank. Very much so an in for a penny in for pound scenario.

Yep. This is my own experience. "A bit" of Co2 just isnt worth the hassle. Either find the sweet spot with your lowtech (mostly i think related to lighting), or go the whole hog with a high tech approach.

 

[foxfish]

There are lots of possible out comes and analogy’s .... so if we have a well set up tank with full on C02, bright light and full EI ferts. The tank is performing very well, the plants and fish are thriving, it has taken months of trying and adjusting but, we then decide ...let’s turn down the C02, we better turn down the lights as well and maybe even adjust the ferts.... will this work?
From my experience.. no it will not! It might after you have battled with algae for a few months and the tank might eventually settle down but I have always given in way before that and turned the gas backup.
The same has happen to me in reverse when I have had a low tech ticking over for years and decided to just add a little bit of gas and it just became an algae farm!
Perhaps starting off with a fresh set up and fresh plants and just a little gas might be an answer?

 

[john dory]

You grow a healthy sword(low tech)and then give it a bit of gas.
The difference is obvious.
If you're aiming for"just enough"i would set the tank up as a low tech...the extra co2 being a booster.

 

[Zeus.]

let’s turn down the C02, we better turn down the lights as well and maybe even adjust the ferts.... will this work?
From my experience.. no it will not!

Yet I ran out of CO2 during first lockdown, reduced lights ferts etc and all was fine for a few months, once able to get CO2 put it back on at a lower level and was fine also, just done same again (CO2 off) as moving very soon

 

[foxfish]

Well that is another outcome...there are just two many variables to set a standard.
Perhaps in years to come there will be more affordable ways to accurately measure all the parameters and we can then set standard settings and offer charts to match C02 and light etc
What we do know now is largely based on full on or nothing, anything in between is a good luck mission but obviously it must be possible.

 

[Courtneybst]

I think it's definitely possible if other parameters are in check.

The reason I even thought about it was because I watched a video from MD fishtanks where he set up a large 4ft aquarium with the intention of it being low energy. He put a tiny Fluval 88g CO2 system in it until the plants got established and then he removed the CO2.

But again, I guess it all depends on how it balances with everything else.

 

[tiger15]

What we do know now is largely based on full on or nothing, anything in between is a good luck mission but obviously it must be possible.

True. You have the Tom Barr EI approach that advocates excessive nutrients dosing, excessive CO2, and large WC to reset. Then you have Walstad approach that advocates no dosing, just rely on fish food and rich soil, no CO2, and no WC to preserve nutrients return from decaying matter.

 

[AverageWhiteBloke]

Perhaps starting off with a fresh set up and fresh plants and just a little gas might be an answer?

Could be the answer mate. I look at it from the pov that if they've never had it then they'll never miss it. Like I said earlier once the co2 is in a plant might find itself in quite a nice little co2 rich spot, as plant mass increases unless you up the flow that same plant can find itself not getting the co2 it craves after it has adapted to have plenty.
Just enough co2 is a gateway drug, my plants had it once but they never inhaled

 

[tiger15]

Yet I ran out of CO2 during first lockdown, reduced lights ferts etc and all was fine for a few months, once able to get CO2 put it back on at a lower level and was fine also, just done same again (CO2 off) as moving very soon

Do you have only low light easy plants? For demanding Dutch stems that need CO2 for life support, many reported immediate bba outbreak running out of CO2 for just a few days.