closed loop system question

[hellssephiroth]

here is an ....unfinished ... pic of what i plan to do i would imagine you guys can figure out what i meant, got tired of messing with the progrem right now. the pump will be the return for my sump and the overflows will feed my sump. theoretically this should work to make it so that i would not need powerheads for circulation correct? let me know your thoughts. this is on a new 120 i purchased and plan on putting a foam wall on the back.

<a href="http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=63670247&albumID=2383805&imageID=37516547"><img src="http://hotlink.myspacecdn.com/images01/23/cfcf9167eb3e1a97f2a6fed71ba083d1/m.jpg" alt="" /></a>

[customcolor]

you need to have returns to be only at the top of your water level or if and when your power goes out ALL your tank (well untill the siphion brake happens on your last return that is) will end up in your sump or FLOOR! closed loop goes from tank to pump back to tank with no sump or filters in the way. that is why its called CLOSED loop. so you will need another pump to run the loop. i would say get the second pump, and ocean motion 4 way of some kind (squirt, super squirt, or reg 4 way) and make the center hole your intake for the pump and the other four returns running off the 4 way.

[AbraxasFrog]

Definitely need a second pump if you wish to have a good circulation without powerheads. Generally, you want a return pump pushing 3-6 times the volume of water through the sump. Depending on what you want to keep, the DT will need 20x-40x (some people use even more) of flow. Separating the two systems will allow you to do this.

Another thought - one intake for a closed loop might not be enough depending on how much flow you are pushing. The intake might create a huge draw that would suck everything up in its path. You could keep the one intake and find a way to diffuse the siphon or split it into two intakes (and tee them together outside the to the recirc pump) so the foce of water being drawn is split between the two.

Thought # 2: Since your return are all on the back, invest in some LocLine so you can direct the flow more specifically. It will help offset the recirc flow from moving back to front and create a more turbulent flow.

[inthedeep2]

http://www.melevsreef.com/closedloop.html
here is an example that i used for an idea on how to set one up.

[hellssephiroth]

what if i just put like 2 check valves right after the pump just in case of power outage? was planning on 2 in case one failed?
the pump i have for a return pump is a gen-x pcx 70.. rated 1537 max head 31.8ft. .... got from a garage sale for $40 no joke, still in box lol brand new the guy said his son was planning to take his tank to college and had to sell it because he couldnt find a place to live that would allow the tank. too bad he sold most of the really good stuff already, ended up finding this in attic a yr later. that should definately be enough to circulate correct? oh .... btw i already have the holes drilled last weekend 1 3/4 inch bulkheads for water flow, also plan on putting valves on each return to tune it a bit. the sump im using is a 70 gallon sump i had made a while back if that matters.

[liveforphysics]

Check valves almost always seem to fail in saltwater after a few months. Some folks say if you remove them and clean them in vinigar every month that they will last, but in my experience, it didn't help.

Check valves also put a lot of additional flow restriction against the pump, which doesn't help your flow out.

[AZDesertRat]

Use your return for just that, a return from the sump to the TOP of the display tank. Check valves are a very poor choice in a reef system as they will fail, could be today could be next week but they will fail guaranteed.
Add a seperate closed loop using the holes you already have drilled. The definition of closed loop is just that, it does not draw water from the sump, it comes from the display, through a pump and back to the display in a completely closed piping system, never open to atmosphere. Flooding won't be a problem since it is a closed piping system so check valves are not needed. Put a few ball valves so you can isolate things for maintenance though.

[hellssephiroth]

hmm so if i do both, sump and closed loop what holes would be my best bet for pump intake/intakes for the loop, and outputs same for sump? thanx for the help guys im not putting it together right now until i get a new place next month im just trying to get my thoughts together so i dont mess up :( if i use the center hole, and maybe one more for reduced suction for intake and say .....2/3 of the other holes for loop and use the last 4th one for sump return would that work? then have the overflows feed the sump? once again thanx for your opinions this is new to me so any good/bad thoughts r more than welcome

[hellssephiroth]

i might just go with the squirt system that looks like a good idea

[tgreene]

Here's how I just configured my new 157g Starphire...

At either end of the base of the plumbing where you see a ball valve, once placed on the stand, I used Spa-Flex to connect to a pair of bottom returns in either front corner.

Also, in regards to the comment from another member above about the need for 20x to 40x turnover rate for a CL, I tend to disagree... Take a look at my comments in this thread: http://www.reefcentral.com/forums/showthread.php?s=&postid=13330612#post13330612

http://gallery.nea-reefkeeping.com/album/00000001/mini-DSC_7101.JPG

http://gallery.nea-reefkeeping.com/album/00000001/mini-DSC_7102.JPG


-Tim

[AZDesertRat]

It looks to me like the only two holes safe to use as returns are the two upper corners you have labelled overflows. They are the only ones high enough to only siphon a manageable amount of water back to the sump in a power outage, all the others will drain half your tank.
If they are in fact truly overflows coming from corner overflow boxes They are drilled too high and you will probably get detritus accumulation in the overflow boxes if they are full depth. Either way, the next best option if they are overflows is use the next two highest holes as sump returns and plumb them inside with 90 degree elbows to get them close to the surface so you don't drain the tank in a power outage. Another option would be over the back returns and use all the remaining holes for the closed loop.
The holes are kind of hard to see but for my closed loop I have a loop suction hole right in the back center next to the offset overflow box and a hole in each upper back corner for the loop returns.
http://i51.photobucket.com/albums/f369/AJOIII/stained5.jpg

The overflow box is drilled in the bottom with the overflow to the sump and a return which I plumbed over the top of the box as seen here:

http://i51.photobucket.com/albums/f369/AJOIII/1eeace49.jpg

[hellssephiroth]

wow tgreene that basically the same drilling i did on the back of my tank :) only thing is is i did 2 corner boxed overflows i was going to use to feed my sump instead of drilling the bottom let me know if it works well i have a while before i set mine up like i said.

[tgreene]

My sump is fed with the internal overflow drains, seen inside the 2 overflows. The sump returns are also inside the internal overflows. All of what you see on my tank, is for the CL.

Based upon your image, I would use the center hole fro a CL drain, then plumb the CL returns to the other 4 holes. Keep in mind however, that the drain must be substantially larger than the returns. Traditionally, most of us would opt for a 1.5" drain, and either 3/4" or 1" returns. I personally use 3/4" CL return bulkheads, because the LocLine itself is only 3/4".

http://a882.ac-images.myspacecdn.com/images01/23/l_cfcf9167eb3e1a97f2a6fed71ba083d1.jpg

[hellssephiroth]

thanx again for the info

[tgreene]

Here's another view of mine, taken immediately after drilling and painting the back and bottom...

http://gallery.nea-reefkeeping.com/album/00000001/mini-DSC_7089.JPG

-Tim

[hellssephiroth]

oh ok ic... very nice work