New CL

[!v@n]

Ok I need some advice on my closed loop. Right now I have three returns coming out of the back wall of my tank, and two returns from my sump on the top of the tank. Im thinking of turning the top two returns into my closed loop, adding 4 more, and a 1" SCWD like the picture below. I know I'm gonna need more flow for sps. I dont want my sand to be stirring around a lot though. I would like to try to avoid powerheads if possible. Im running a gen-x 40 pump as my closed loop now but im gonna upgrade and use that as my return for the sump What size pump should I use that will give me plenty of flow for sps but isnt gonna cause a sandstorm.

[JHAI4]

Start with the desired amount of flow you want in your tank and then start the process of estimating head-loss (use reefcentral head loss calculator) to conclude as to which pump meets your needs.

125g display
I desire 20x?
= 2,500gph

Now how much head loss will you sustain in plumbing? and how much flow will you get from the sump returns? What diameter pipe (1", 1.5")? This should get you started....

[JHAI4]

Here is my spreadsheet calculating my flow from my closed loops, returns and VorTech.

[kpick41]

I built a CL similar to the one on Melev's site (http://www.melevsreef.com/closedloop.html), but I added eductors to the 2 outputs since the SCWD will significantly reduce the flow that the pump can output.

http://www.thereeftank.com/forums/f1...tor-23330.html

This thread (simpler) is a little different from the one I built from but I was able to build mine with ABS (the black PVC) and they are easy to make, effective, and cool looking. Tough part was finding the plumbing parts had to hit up Lowes and HD.

Also coming up from the pump to the outputs I added a ball valve so I can control the flow. Some may say that this is probably not good for the pump but 2 years later and running strong! Constricting the flow has potential to add heat to the pump, but your CL pump shouldn't be in the water anyway, so no worries.

I'm really glad I added the valve now because in full open I get a lot of microbubbles due to cavitation in the pump (not sure if it's the SCWD, the eductors, or the head pressure causing it, or a combo of them). I close the valve ever so slightly and all is bliss...great wave action flow.

Oh yeah, I also added a union and tee'd off a drain with a valve from the input side. that way I can just remove the pump if I need to service it and don't have to remove any plumbing from the tank.

You said your sump is above your tank so I assume you have room to put your CL pump on a shelf up there? If so, realize you will not have as much head loss since your pump will be pushing water downhill to the tank, but if you input to the pump is in the tank (not the sump) like Melev's CL then the pump will have to pull that water up which accounts for something but probably not as much.

If I remember correctly the SCWD does have a max input flow rating. I definitely wouldn't go bigger than that.

Anyways, food for thought and some ideas.

[!v@n]

I didnt mean the sump is above my tank, the returns for my sump are drilled on the top of my tank. The sump itself in the garage through the wall and about 5 to 6 feet below the tank itself.

[kpick41]

All else applies then, but you will have to factor head loss for the pump you choose, most will have it on the box.