# CO2 by natural means!



## Jaap (Jun 24, 2005)

I have a 30 gallon tank (120 litres) with the following setup for the past 4 years:

1. Layers of substrate and fine gravel, which I don't know what the substrate is.
2. A driftwood
3. 3 species of plants that are hardy since they are the only plants that managed to survive a period where I completely neglected the tank. One of the species is Valesneria I think which is a fast grower, green leaved long plant. The other specie I think is Baby Tears or something. Forgive me for I do not know the names of the three species of plant I have for 3 years now.
4. Just purchased 4 mollies and recently one of them gave birth to around 20 babies.
5. kH 4
6. pH 8 - 9 
7. One 25 watt Arcadia fluorescent lamp (Pink colour)
8. Two 25 watt Arcadia fluorescent lamp (White colour)
9. The tank has no top and the lamps are adjusted 30 cm above water level, where the depth of the tank is around 42 cm
10. Due to the hot climate in the summer, now my tank has a temperature of 31 degrees celcius and is not exposed to any sunlight at all.

Before I purchased the fish I had a DIY CO2 system with sugar and yeast but after reading a book I understood the reasons why my plants did not grow. Now that I have the mollies the plants grow better but I don't want to risk the fish by adding CO2 since many fish died because of this since I started this hobby. Now I am making a clean start and my vision is to create this balanced ecosystem with just mollies or any other community fish, many plants, no algae and no CO2 gudgets. I currently have hair algaem, thats why I added the mollies. The mollies didn't help much.

Why do I have a 1.2 ppm for CO2? This is the reaon why my plants don't grow I believe.
How many fish must I add to have enough CO2 and to maintain a balance so my tank doesn't get overcrowded?
How do I get rid of the hair algae? I suppose by having a healthy plant growth.

Please give me a few tips on how to create this ecosystem that I want. I have a limited supply of fish and plant species from my LFS. 
My main task is ofcourse to increase co2 by natural means!


----------



## Urkevitz (Oct 26, 2004)

Your lights are way too high above your tank, I would get them as close as possible to the water surface, then you should get better growth.


----------



## Phil Edwards (Jan 22, 2004)

Hello, hadjici. Welcome to APC! 


The tank has no top and the lamps are adjusted 30 cm above water level, where the depth of the tank is around 42 cm

*That's a lot of distance between your lights and the substrate. Try to get them closer to the water in order to increase their illumination. Most fluorescent lights aren't strong enough to put much light through half a meter of water. 

10. Due to the hot climate in the summer, now my tank has a temperature of 31 degrees celcius and is not exposed to any sunlight at all.

*This could be problematic. 31 Celsius is pushing the limit of many species ability to efficienty photosynthesize even at high CO2 concentration, which your tank doesn't have. (more on that farther down) Is there any way you could place a fan near the tank so it blows across the top of the water? The evaporation will help keep the temperatures down somewhat.

Before I purchased the fish I had a DIY CO2 system with sugar and yeast but after reading a book I understood the reasons why my plants did not grow.

*Adding any CO2 would help. I don't think using a yeast generator directly killed your plants. It sounds as though they weren't receiving sufficient mineral nutrients. Without the CO2 supplimentation chances are high that the carbon limitation was stronger than the mineral limitation. When you supplimented CO2 the plants' photosynthetic and respiratory mechanisms started working faster than the plant could uptake minerals to sustain the new growth and the plants eventually died. 

Now that I have the mollies the plants grow better but I don't want to risk the fish by adding CO2 since many fish died because of this since I started this hobby. 

*Adding CO2 isn't a bad thing. Most of us here do it and our fish are just fine. Do you know what the Carbonate Hardness (KH) of your water is? 

Why do I have a 1.2 ppm for CO2? This is the reaon why my plants don't grow I believe.

*Decomposition of fish food and diffusion of CO2 from the atmosphere will cause natural low levels of CO2 in the water. You're right about the low level being why your plants don't grow much, if at all. Lack of mineral nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium and trace elements is another contributing factor.

How many fish must I add to have enough CO2 and to maintain a balance so my tank doesn't get overcrowded?

*You're going to need a lot of fish in that tank to naturally provide the amount of CO2 your plants need. Unfortunately at those levels you're going to have excessive levels of ammonia and that will cause algae. Increasing your fish load and starting up the yeast generator again should work well. 

How do I get rid of the hair algae? I suppose by having a healthy plant growth.

*The cause of your algae lies in your plants' inability to take up nutrients and grow well. Getting your plants healthy and growing well will naturally reduce your algae issues. 

Please give me a few tips on how to create this ecosystem that I want. I have a limited supply of fish and plant species from my LFS. 
My main task is ofcourse to increase co2 by natural means!

*If you want to increase CO2 by natural means you can add top soil to the bottom layers of your substrate. Read "The Ecology of the Planted Aquarium" by Diana Walstad, natural means is what the book is all about. 

*Asking questions like these around here at APC is another good way of getting help. 


I hope this has helped somewhat, even if it's only to help you think of more questions to ask. Good luck! 

Regards,
Phil


----------



## Jaap (Jun 24, 2005)

I have read that book and it is great....unfortunately I dont want to disturb my current setup....if I add DIY CO2 will I leave it 24-7 in my tank without adding an airstone? When my tank is finally filled up with my current plants due to growing, and then I remove the CO2, will the plants stay alive and grow slower or will they die?


----------



## trenac (Jul 16, 2004)

Once you remove the C02 you will see a decline in plant growth, try using Seachem Excel (carbon source). You will not see the same results as you would with C02, but it would be an improvement over no carbon source.


----------



## HeyPK (Jan 23, 2004)

Some aquarium plants are much better adapted to getting CO2 when it is at low levels. The plants with finely dissected, thin leaves, such as Elodea, Egeria, Lagarosiphon, Myriophyllum and Ceratophyllum are good at this. So are the old fashioned Amazon swords---the ones that do better submersed than emersed. Vallisneria is good. Basically, consider all the old fashioned plants that were popular before CO2 fertilization was widely used. 

Better keep an eye on your pH! When it gets up to 9, that is getting pretty rough on most tropical fish species.


----------

