I have 9 marble crays in a 55 gal ph is 7.2 no amonia no nitrate, its been 4 months and no berries yet the largest is 4", how much longer my oscars ,managuense and blue texas are geting inpasient
i would add some veggie pellet or something like blanched zucchini or other calcium rich vegetables. Algae wafers (depending on brand) often are mainly fish meal, so a protein based food.
brocolli is good, but the florets tend to fall apart. spinach is fine as well, but don't blanch it for the same reason. My favorite vegetables to feed are frozen french cut green beans (great portion size and no prep necessary other than using something to sink them) and zucchini, which I just cut into a small spear and sink. Here is a list of calcium content of vegetables: http://www.aquariacentral.com/forums/showthread.php?p=1943633#post1943633