Iv bought a load of sand for my tank itās dull and Iām not a fan it was cheap I have to say but itās natural and smooth and was one of the only sands there that was fit for purpose regardless of how it looks I bought it , financially after moving house I canāt be picky ahahah but just in eye line with the sand shelves was peppered corys , I instantly encouraged my daughter to look at them so lure in the wife maybe she will let me spend my own money on them lol ,,, it worked I bought them all , that was 5 not as many as I would of liked but I thought the number was large enough to make them still feel kinda comfortable so I rush home removed 70% of my gravel and cleaned and added the sand added some bottled bacteria because I worry then added my fish after floating them for say 5-10 mins , one of the five is killing it swimming around eating being Iād say overly confident for a little fella in a big world swimming to the top doing dive bombs all the way back down ,not constantly saw it do it twice I have nothing gasping at the top so canāt be oxygen problem but the other 4 I have not saw at all I have lots of wood and hiding places so Iām guessing they are just scared and I know I 5 isnāt really enough for a 5ft 500l , just not sure why one of five is being Jack the lad and the others and cacking it