Tom Barr;26085 said:The point I made was more about established vs new introduction.
Adding a plant to a dense bed of weeds vs adding it an open area..........where would you predict it might do better?[
Well, OK, at first thought I'd say that it would grow better in an open area.
But after thinking, I wondered why the "open area" is "open"? Why aren't plants growing there already?
If instead I planted the new plant in the middle of the established plants, ignoring any blocking from the sunlight, why do you think it wouldn't grow there? What defenses would the established plants use to keep it from growing?
To be fair, take one of each plant type and place them in an open area. Then see.
I have small numbers of the crypts in question in three other tanks and they are living in harmony with other plants. In the tank in question there are 40 to 50 crypts, confined to half of the tank. Maybe there is a tipping point somewhere?