CO2 And The Smaller Aquarium

 
I would be grateful for some advice around using CO2 for my plants. I will be using a 64ltr tank with internal filter and strong LED lighting programmed for 10 hours on. Gravel substrate and some bogwood. I have kept fish for many years but never really considered the health of the plants.    🐠🐟🐚🐟🐠🐚🐡

If you have enough fish in the tank, they should produce enough CO₂. I very rarely vacuum the substrate and the fish poo provides all the fertiliser needed. But I do have quite hard water and started with a layer of soil under the gravel and so if you just use pure gravel, or have soft water, you may find things different.

There is a relationship between CO₂ and hardness, which is often forgotten. Many aquatic plants can use bicarbonate ions as their source of carbon, rather than CO₂. So if you have high carbonate hardness in your water, additional CO₂  would probably make little difference, whereas if you have soft water it would probably be more significant. I wonder what Easycarbo contains, maybe just bicarbonate??

Anyway, my point was that I have some tanks of similar size to the one you mention, with hard water and a full load of fish, plus an under gravel soil substrate, and the plants grow like crazy without any additional CO₂. Rather than trying to make them grow better, I have to prune and remove some regularly. In my case, additional CO₂ would be a waste of money and effort since my plants grow very well without it.

The only time I have found that the plants didn't grow so well was when I had just a few fish in a tank. Fish produce plenty of CO₂  which should be enough in a normally stocked tank. When I increased the stocking to the normal level, the plants really took off. However, most aquascaped tanks have a lot of plants and very few fish, which is no doubt why they find it necessary to use some sort of CO₂ generator.

I was given one of those CO₂ generators which use a sugar and yeast mixture, but it required very regular emptying and refilling and I really couldn't recommend anything of that type.

You also mention a gravel substrate. Many people find that plants don't grow well in plain gravel and I'd certainly start by using fertiliser root tablets first. There is always one limiting factor to plant growth and if they are short of one or more nutrients, they won't grow any better however much extra CO₂  is added. The same principle applies to light, increasing the intensity or duration of light will not make the plants grow any better unless light is the limiting factor. The concept of limiting factors is based on Liebig's Law of the Minimum, which states that growth is controlled not by the total amount of resources available, but by the scarcest resource. So you need to find out which is the scarcest resource, if it isn't CO₂ then it is a waste of time increasing it.