I would not put 30-40 cichlids in a 125 unless they were dwarfs, nor would I knock myself out with plants. I keep mine in a PH of 6.4-6.8 and I do not heave health or breeding problems. My water matches the LFS water and they rarely have deaths. I also waited almost 2 months before picking them up. I had plenty of opportunity to observe them for health and other concerns before I bought them. Many of the African Cichlids like to rearrange the tank and that's why I don't bother with plants. I also like to make sure they have plenty of swimming area and sufficient room for breeding.