My 29 gal tank is 15 months old, very heavily planted, with 2 SAE's, 5 Rasboras, and 19 Tetras. Ammonia, nitrite, and nitrate are always zero, pH always 6.0 (my API test kit doesn't go any lower). The SAE's are my favorites, but I hardly ever see them anymore, just the dominant one during morning feeding. Both looked in good color and weight on the rare occasion when they appeared together. Where they spend their time I can't tell because the plant growth is so thick. Both are about 3 1/2" long and a year old. Is it normal behavior to remain hidden all day? I do miss them. Thanks