I have a 100 gallon 60Lx18Wx24T
My current closed loop consists of a 2" BH feeding a 1200gph Iwaki that feeds 2x 1" BH that each split into 2x 3/4" locline. so right now i have a total of 4 outputs. i will be replacing my submersable return pump with the iwaki.

I have purchased a dart and a 4 way and im starting the planning process the drum is a V1. and now is where the help is needed.

Q1) the intake for my closed loop is about 2.5-3.5 in above my DSB im not sure if the intake from the dart will be powerful enough to pull sugar sand off the DSB. i am concerned about this because of pictures that i have seen where drums have been scratched to death by the sand.

my solution if this would be a problem is to put an elbow facing upward to elevate the screen from the sand bed.

Q2)i am curious what this hammering is and how to prevent it. if i have the 4 way 4 ft away from the head of the pump will that cause it in the pipe in between?

Q3) i am thinking about running outlet 1 up and over the left side of the tank and with the same style of lockline of a double 3/4 outlet i want to point that towards the reef wall on the back of the tank. Outlet 2 will hook up to the 1" BH on the left which is 3 in from the top of the tank and about 14" from the left side. outlet 3 will be the same as 1 but on the right and 4 will be the same as 2 but on the right as well.

is that enough outlets on each output to provide efficeint flow out of the dart. (if needed i am prepared to add more outlets if needed. oh im also thinking about using edductors or penductors (which one is what i want i have seen them called the diffrent names).

Q4) should i use flex pvc or hard plumb it i know there will be alot of angle changes and i think the flex would help save some of the flow


Q5) is that deisgn stated going to provide
Random flow
Wave motion
efficnet use of equipment

if not what can i do to make that happen


hope you like the MS paint drawing