I'm not 100% positive on this but I think you will get a slight pinching effect, but, I think you actually want this because of the multiple outlets. You want the manifold line to be slightly pressurized so that each nozzle outputs more or less the same flow as any other. Otherwise, water will just mostly go out the first nozzle and the further away each nozzle will have less and less flow.

Overall the multiple outlets will compensate for each individual outlet having a slight reduction, so it's not like you're not getting the most bang for the buck on the pump.

Yeah thats exactly what I was thinking. Each outlet will get that slight pinching effect but after thinking about it, I thought that might help, especially because the pump is fed up on the right side. I was worried that most of the flow will be just the right. I still think the right will get more flow from the closed loop BUT the return from the sump will be on the left and should even things out.

Anyways, I hope this works because I am out of ideas if not and I really like how this looks...Or really how its not very noticable. The ABS is very easy to work with and is much smaller and thinner than PVC. Already black too!

If anyone else thinks theres a problem though, can you please let me know soon because I want to cement the parts that will be cemented. I should be able to do a fresh water test of the whole system on saturday!

Looks good. But, I wouldnt rule out the possibility of having to go to even smaller nozzles. Basically, to pressurize the loop a bit, the are of all the nozzles will have to add up to less than the area of the feed pipe. You might even get good results going to 3/4" outlets?? Freshwater test will tell you, and as long as you dont cement the nozzles in, which I wouldnt anyways for cleaning purposes, you can adapt down to smaller real easily. I'd fill tank to just below nozzles and try it, if your drain/overflow will allow that. That way you can see the water coming from each pipe easily.

Yeah I can probably fill it a bit lower for the test. Im not so sure about anything lower than 1.5" nozzles though. I really don't want to reduce from 2" to something like 3/4" or I may as well have used a much smaller pump too. I think this pump at 6000 GPH can give good flow to all the outlets even at 1.5". I could be wrong though.

The nozzles will not be cemented in either because I do not want them stuck in one place. The tank is so shallow that Im sure this will give more than enough flow to the whole thing and then some.

Ahh yes, 6000GPH Somehow I missed that. I will be interested to see how she works :D Just got my top loop for the 45g done tonight. Most of the other plumbing done as well. Just need to find a reasonably priced 36" tank for my Freshwater fish, so I can steal their present tank for the sump LOL

It looks GREAT.

Like how you got the 45° set up, you're making your own Omni Flex nozzles

Close the loop to more evenly balance flow from all outlets (reference here). And you know the manifold has to be good, Holmes on Holmes pushes the manifold for houses)

Get so water in there and try it out.

Yeah your closed loop looked great! When do you figure you can have it all going by? If your like me, your getting really impatient! Well honestly, my fish are the ones getting really impatient...

Oh yeah its going to be all closed for sure. I had thought about doing half of one type thing but realized it would never work as well. I am going to cement the actually manifold tonight except of course all the outlets. I hope I can keep the outlets "uncemented", even the black reducers you see in the pics but I thought the pressure might be a bit much and eventually pop out the reducers. I guess cementing them in is ok but I like to have the option of changing still if I want.

Well, I'm hopin to have water by end of the month, better be sooner HAHAHA. We just re arranged the living room tonigth, put the tank in another corner. And then I did the smart thing and checked my finances....I'll be over in the corner here sobbing uncontrollably LMAO

I hear you about the finances! I can not really change or add much for a good long while now. Even going today to get the ABS stuff for the outlets ended up being like $50...not so bad BUT when you add up all the $50 trips, it gets a little crazy. Well over $2000 now. Im pretty excited to get some fresh water in it saturday and then if all goes well, drain it and start adding RO water maybe Monday or Tuesday. I want to get the LR in the tank by next Tuesday or Wednesday and see if there is a bit of a cycle which I expect. We will see though if that all goes as planned. Nothing really has so far!