I've made a purchase today that includes an additional Tunze 6105 that will be added to my current flow system of one MP60 and one Tunze 6105. All three combined have a capacity of 80x the display in flow. I think this final form of the flow system will ensure that the newly added rock will not creat a single dead spot, not that I have any now.
I have also purchased the needed equipment and fittings to make a ****** mixing station with a capacity of 110 gallons. Will include a RO shutoff float valve, Iwaki 30 for mixing and transporting RO/Salt water. I was able to save a lot of money by eliminating expensive ball valves. Sure all those valves could have a use at some point however does it justify the cost and in my case, no way.
I will fill, mix, and change ~100 gallons at a time. For now I will do it manually but there are plans to have an automatic water change system put in place. All this is leading to that but will eliminate a lot of monitoring and labor I have to do inoder to accomplish a simple water change now.