Do plants always need fertilizer, Micronutrients and Macronutrients

[maverick786us]

A 3 months old heavily planted cycled tank, that has pressurized CO2, and fish waste and uneaten food is food source for plants (ammonia from it broken into nitrates), do plants always need fertilizer, Micronutrients and Macronutrients to consume nitrate and CO2?

 

[ElleDee]

They need nutrients one way or another, yes.

There are many potential sources of nutrients besides fertilizer (tap water, fish waste, soil, certain rocks), but all these sources are highly variable and can be hard to quantify. Some nutrients are harder to come by through these routes than others. How can you be sure your plants are getting enough of all the different elements they need? The more plants you have and the faster they grow, the more nutrients they will need. Most of us add fertilizer to be sure we have all of our bases covered, though there are many different approaches about how to do that.

 

[simon_the_plant_nerd]

do plants always need fertilizer, Micronutrients and Macronutrients to consume nitrate and CO2?

Yes. You would die without food. Also plants. Plants like you can go some time without food but ultimately, without nutrients they will die.

 

[maverick786us]

OK initially I thought a fully cycled planted tank get its nutrients from fish waste and uneaten food. Then one day I was shocked when I discovered that, my 3 months old heavily planted tank had nitrate level bit high. I did my research and I got questions from some of the experts, that how frequently do I dose fertilizers, nutrients (micronutrients and macronutrients) to these plants. The experts said that plants need those doses to CONSUME nitrates and CO2. I was bit puzzled that nitrate is already a natural fertilizer / food for plants and the plants need extra bit of nutrients to consume their basic food?

Regardless I increased the dose of fertilizer and nutrients (micronutrients and maconutrients ) to twice a week. But somehow I felt it wasn't adequate for the plants, because I didn't see the plants develop vibrant color, it was a non CO2 tank, but I was using liquid CO2, I thought its a substitute to pressure injected CO2.

One day I met a guy who is into aquascaping and he made some really good aquascape with carpet grass and background plants. I asked him which fertilizer, and nutrients formula he is being giving to his plants. He said he as 5 massive sized tank (50 gallon) and for such a large quantity of water it will cost him a fortune for fertilizer and nutrients. He said he let plants get nutrients naturally from fish waste and uneaten food.

So let me rephrase my question. Without fertilizer, nutrients (micronutrients and macronutrients), from external sources the plants will not consume nitrates and CO2 at all?