Hi Disciple & Fishmosy, will try to get some good photos of each tank tomorrow & will provide details. What I can tell you now is, its nothing to fancy, basically I have cherries, Tb's, TBM's, CRS, mischlings & tang tigers. Hi Inverted, I originally thought the rusty SS strainers were causing the pH & GH issues. I know feel it was my inexperience with TB WP, that lead me to jump the gun and blame the rusty strainers. I’m now sure that the general rise in TDS from 145-150 to 170-180 also increased the GH. I still fairly new at this. My current problem is directly related to adding the 5 new tanks (bottom row) to the system. The problems I encountered were 1) underestimating the impact of adding 200 ltrs of tank water (5 tanks) with a pH of 5.4 to approximately 600lts with a pH of 6.4. The 5 tanks had fully cycled and I add 1 tank at a time to the existing system over 5 days. Within a few week the deaths stated & monitoring the WP of the different tanks showed that different WP in different tanks. It’s taken about 4 weeks for the system to find its balances with all tanks having the same WP. So if anyone like builds a rack and plans to add different tanks time over 6-8 months due to cost, are likely to run into the same problems with multiply deaths.