I'm looking to use my Ebi tank to start a Sakura colony, with the idea being that any excess numbers will be moved into my other tanks to improve the RCS bloodlines in there. I got 4 about 6 weeks or so ago, 2 male and 2 female (I think, I'm no guru!). I lost a male about 2 weeks in, but all others seem fine. I've come home today to find the other male dead. Both had dark marks on the underside, although I'm guessing that could just be a clearer view of their internals as they've got less opaque after death? The females (larger, darker coloured) seem fine in the tank. pH 7, Temp 24C, low tech tank dosing all-in-one, mature substrate, good filtration and flow, TDS 290, gH at the tap is really soft. My Rio 180 has a huge RCS colony in there with the same water parameters and it's going from strength to strength. I rescaped the tank last weekend, but used the existing substrate in the tank etc, so can't see any issue there. I wouldn't normally post up, since the sad truth is that from time to time you lose some livestock, it's just less noticeable in a larger tank because remains get scavenged more quickly. Since I want to put an initial stock of Sakura in the Ebi though, and they're not cheap (say I add 10 shrimp, that'll be £30!), irrespective of the fact that I'd rather not risk their little lives,I am trying to get rid of my worry/anxiety that there is a tank issue rather than bad luck. I don't believe the females are berried, which was going to be my hope to stock up the tank - they're so heavily coloured that I can't see through them, so can't tell if they're saddled or berried.