Why is that?
Both use the same nutrients.
The issue is an ecological issue, not a competition.
If you add fresh well growing algae and plants in equal amounts, the algae will grow as well.
What occurs is germination of algae spores in our tanks in response to a parameter, Typically CO2
/NH4. Does not take that much and more light means it'll happen faster and be more sensitive.
Once there are adult algae then it's tough to get rid of it.
The key in new growth.
Stop that, and you stop algae.
We do not raise plants from seed, algae produces lots of spores and they run through various sexual cycles in our tanks.
Plants do not.
We add lots of plant biomass, produce them vegetatively, algae are induced to grow using NH4/CO2
I think folks like to use the word phrase "out compete" without considering what that means.
Many folks use that phrase for some reason.........
When the levels of CO2
are good, the NH4 uptake is rapid and O2
levels are also high, so the plants control the environment, not the other way around..........at least when you have enough plant biomass and feed them well so they can maintain a good growth rates/uptake of NH4.
Both algae and plants can and do use NO3
..........but that does not induce/germinate algae blooms...........