deadts was start like no reason, I wasn't change anything, just weekly same water change (%10 - 15), I'm using Ro water, not with minerals, deaths start before water type changes , I did chage water type 1 week ago, ,tds was 160 ppm when deaths start, and I think maybe  lower tds is will be better for shrimp and I get lower tds to 140 now, I know it's a lot but shrimps already dying and I have nothing left to do,  I have left 3 shrimps now, 3 shrinps look good for now, no any deaths for 1 days. I think I should get KH test. if this 3 shrimps die too I will give up I think.. I use Ista shrimp soil 5.5

It does look like a moulting problem still! Where are you on water, from the above you started RO, then went to mineral water and now gone back to RO? Is this latest RO with the added minerals for drinking or a new one? Moulting problems are probably the most common cause of problems with shrimp. You say you had no deaths for a while, did this tie in with one of these water type changes, ie have you only recently gone back to RO and that restarted the deaths? Changing water (especially when with water with different parameters from the aquarium) encourages them to moult so messing with the water as you have been is likely to have been some of the problem. What substrate are you using? How many shrimps do you have left? Calcium is included in the GH test (and magnesium) and that looks about right, though those 2 could be out of proportion. There is a test kit for just Calcium. As crabby says, it would be a good idea though to test KH, for caridina shrimp there should be little to none?  Simon

Been a while since I posted in here. Currently running 3 racks but getting a bit too much with family/kids/work commitments. Finally decided to shut down this rack so it is now for sale if anyone is keen. I am in Brisbane. Send me a PM if you would like to view it. Also have heaps of other stuff for sale e.g. Biospon filters, Eheim 2213 and 2215, a few Hailea HC-250A chillers, etc. See my sale post here:  Cheers, JC

I think that there are calcium test kits. A KH test kit may also be of use. But I'm not sure - jayc or someone else will probably know much more than I do on this matter.

I don't know calcium content, how can I know that?, with test kit? and how can I lowe calcium level?  yes when shrimps is die there is shell piece mostly