please help with plumbing and flow PLEASE!!!

[Black71gp]

tank 292. 72x36x26high. acyrlic. pennisula style. one overflow on one end. return pump is iwaki 100 with four eductors. flowing towards the overflow. I currently have a sequence hammerhead. I would like to trade it for a dart and get another dart and run two darts for my close loop pumps. I really do not want to see much plumbing or powerheads in the tank. I was thinking of having the closed loop drains be on the same side as the overflow.. maybe midway or 3/4 up from the bottom for ease of cleaning. but i do not know what to do as far as the returns from the. I will be running barebottom.. and mixed.. mostly sps. i want something to flow across the bottom to keep detrius up. i am going to put all my rocks on small pegs. maybe two 1.5 inch returns blowing across the bottom of the tank from one dart, and maybe two at the top blowing across from the other dart? has anyone ever used those spa jets that turn in circles? for back massage. i was thinking that would be a cool random flow? please if you read this and have any thought or advise let me know
thank you
jarrod

 

[Black71gp]

any thoughts? at all

 

[javajaws]

2 1.5" returns on 1 Dart I don't think will have much velocity to be effective in a 72" long tank. It would be better if you could alternate flow between 2 1.5" returns such that only 1 is flowing at a time. Or maybe consider 2 1" returns per Dart...though I'm not sure how the Dart would handle the pressure for that.

 

[Black71gp]

how about my current hammerhead. i was just thinking two darts give you more flow and less power useage than the hammerhead

 

[tgunn]

On my 140 (4 foot long) I started out with a Dart.
In my initial testing I tried two 1.5" outlets. They each one could be felt up until about 3/4 the length; more of a gently diffuse flow though. If I closed the ball valve on one outlet the flow could definitely be felt on the other end of the tank.

At one point in my initial testing and setup phase I tried 1" bushings on the two 1.5" outlet. The flow was certainly strong out of the bushings but I found it didn't provide as much overall mixing in the tank as the two 1.5" ones; this lead me to believe that I was getting a fair bit of back pressure losses.

I am currently running a Sequence 1000 5000SEQ22 on my closed loop (similar to a hammerhead).. I've got two 1 1/2" outlets, two 3/4" and a 1" outlet. My goal was strong diffuse flow throughout the tank and this worked great.