If you are trying to keep difficult red plants, or if your plants in general are not growing well, or if you have constant algae issues in your planted aquarium, most probably it should be due to lack or co2 or fluctuation in co2 level in your planted aquarium. The right amount of CO2 to be injected differs from aquarium to aquarium , hoe ever lets try and make this as simple as possible.
If you own a 60p aquarium ie, 60cm*30cm*36cm , you would have heard that a CO2 injection of 1 bubble per second is the right amount to be injected, If you have done some research online or through books. Theat is not totally wrong however, every aquarium is different depending on the way its setup.
-The tank contents are different.
-The water quality is different.
-And the daily management method is also different.
– The equipment stack would also be different.
1 bubble per second for a 60p in most cases is not sufficient. There is basically no problem if you add more CO2 than you think. There are 3 factors to be considered while doing this, which will be explained later in this article.
Recommended injection is about 2-3 bubbles per second for 60p tank but, if you are having epiphytes only tank or if you light is not of high power and your fertilisation is also very lean, you may still stick with 1 bubble per second.
On the other hand, if you want to grow a lot of really beautiful and colourful plants and want to have say a dutch style aquarium, or want to keep high demand plants healthy , you must inject 2-3 bubbles per second for a 60cm aquarium. If you have a lot of surface agitation , you may even want to consider increasing the injection.
Three simple factors to be considered when increasing co2 injection.
- FIshes
You might have guessed it. Yes, fishes and shrimps are the first ones to react if the co2 injection is too high in the aquarium. Fish would come gasping at the surface of water deprived of oxygen. In this case, you should reduce the co2 injection in general. But as an immediate action, one should start aeration and change water if needed, to save the fish from death due to co2 poisoning.
Shrimps on the other hand, would stop moving, if co2 is excess. Immediate remedial action is same however, before concluding a co2 poisoning, do check if your other water parameters are fine. Because, shrimps would say put, if any water conditions are not favourable as well.
In short, watch how your fishes or shrimps react when you increase co2 injection.
- Water Temperature
Consider reducing the co2 injection during summers. This is because as the water temperature rises , oxygen availability decreases. Hence if you keep injecting more CO2 during summer or if your water temperature in general is say more than 27 degrees, it will be counterproductive and cause threats to fish , shrimps and also would contribute to quick triggering of Cyanobacteria out break. Also, the oxygen availability at substrate level also would go down.
- Biofilm in Surface
The reason why co2 injection at higher rate often does not affect the live stock in an aquarium is because, the CO2 escaped through gaseous exchange from the water surface. Flow of HOB filters or rain bar sprays from canisters create a lot fo surface agitation escaping a lot of co2 from aquarium water. When biofilm (will explain about this in detail in another article) gets formed on the surface of water , this gaseous exchange gets affected and co2 builts up in water. Hence when injecting co2 you should take care to keep the water surface clean may be by using a small surface skimmer.
Will higher CO2 injection affect the PH when the aquasoil is new?
If the water PH is below 6.3 before you start injection CO2 , it would not be advisable to to inject higher amount of CO2, as this will further reduce the PH and this wont be preferred by some plants and most fishes. This might be because when the soil is new, it buffers a lot and slowly this should stabilise at around PH of 6.7- 7 and then it would be safe to inject the higher amount.
To sum up,
For 30cm cube – 1 bubble per second
For 60p – 2-3 bubbles per second
For 90p – 3-5 bubbles per second
For 120p – 5-7 bubbles per second
Could be the ideal injection rate. However, do keep in mind that this changed from tank to tank.
