Closed loop

[Krazykarl]

Can someone please help me understand this theory of a closed loop overflow system? I'm trying to plan out the plumbing and baffle design of my sump and someone suggested running a closed loop system. I've googled this but I can't find out much info on it's purpose or how to build it. All I really plan on doing is having my hob overflow box drain into my 55, pass thru a series of baffles, skimmer, live rock and thus pumping this water back up to the dt with the return pump. Is this too simple? Help please

 

[marks69]

a closed loop doesn't go through your sump.  you have a separate drain, direct to the pump and back to the tank.  if your drilling your tank you need another 1 1/2" drain well below the water line. 

 

[Krazykarl]

I'm not drilling the tank. I'm using my eshopps overflow to drain into my sump. What's the point of a closed loop if it doesn't go thru your sump. Isn't the point of a sump to house equipment and lr

 

[Blob-79]

closed loops are alternatives to create more flow in your tank without having to use powerheads

 

[shayneh]

A closed loop ads to the overall water flow in your system and helps to keep detritus suspended so your overflow can take care of it, much the same way that powerheads do but without all the cords (aka electrical hazards). Here is a design that can be upsized to suit your particular application for an undrilled tank:

http://www.melevsreef.com/closedloop.html

As for your flow through the sump....It should only be about the same amount of flow as your protein skimmer is capable of processing.... anything more is a waste and does nothing to benefit your system.

 

[Krazykarl]

Awesome. Now I get it. Seems like a little bit of work considering I already have all the powerheads. Do you think that 1900 gph is too much flow then for a return pump? I thought I read that you should turn over your tank volume 10 tims. I have 190 gallons total water therefore I thought a 1900 gph pump was right. All that will be in the sump is rock skimmer and heater. Please help before ibbuild this damn thing

 

[shayneh]

Depends on what type of coral/livestock you plan to keep. For instance I am setting up a 75 gallon display with 40 gallon sump. My display will have a reeflo snapper running the closed loop at approximately 2500gph and the return from the sump will be 700gph but on a switching current water director so actual output will be about 500gph. So overall turnover will be just shy of 30X and my tank will be sps dominated.

10X in all honesty is about the minimum you want....trust me your fish will thank you for all the flow you can get since the ocean is wayyyyy higher than what we can affordably provide.

 

[fishit]

you dont want to run 1900 gph through a 55 gal sump thats way to mutch flow for the sump to do what is suposed to do
also check your pump because a pump may be say 1200gph but that right out of the pump so at say 4 feet it might be 750gph also depends how you plumb it  and  if your using the same over flow i seen in the pic of your 55 that looks like the eshopps 1200gph system so you can not put a bigger pump than your over flow can handle or could over flow your tank

 

[Cal_stir]

run a bypass in your return line back to the sump so you can tune your overflow, i run @ 3000 gph thru my 80 gal sump, with 150 lbs live rock, skimmer, 4 returns, no powerheads, it works good for me

 

[Krazykarl]

Ok. So what should I do? The overflow I have is the eshopps yea, and it's rated for 1200 gph. I get that I can't exceed that or I'll overflow. An idea I had was to plumb one side of the overflow to the 1900 gph and the other side could drain down into my sump. Run a 500 gph return in the sump back to tank. I can build a Bypass on the return line from the 1900 gph and redirect it to the sump so to tune the overflow. The other pump will run full tilt. Is this feesable? Or should I avoid all this, run just the 1900 gph in the sump, with a bypass so I can achieve the 1200 gph and have the rest drain back into the sump. Only thing in the sump will be rocks, heaters, skimmer. Anyone wanna gimme ideas?

 

[marks69]

personally i would find a drilled tank.  i had a hob overflow and it was nothing but trouble.  drilling glass isn't hard but a 55 is usually tempered(don't ask how i know.lol)

 

[shayneh]

Ha ha ha marks69 I would have loved to have seen your face when the glass exploded......(ooh! look at all the sparkly diamonds on the floor) HOB's can be a pain in the ass since they can lose full siphon ability with very little amounts of air trapped in them. I recommend drilling also so you can go on vacation without worrying if your return pump is smoking hot and all the water from your sump has now overflowed the tank and saltwater is sitting on your floor ruining everything it comes in contact with.....yes I had it happen! 

I still recommend using that 1900gph pump as your closed loop pump (independant of everything else) and running something smaller from the sump, or sell it and get a smaller return pump and run powerheads in the display, or branch it off with ball valves to run phos/carbon reactors (or ??) as well as the return. Just remember not to restrict the intake (not recommended on most pumps).

You can't connect your pump to the overflow as it will create the worst sucking noise and start cavitating which will then create tons of micro bubbles in the system which will then collect in the overflow which will slow the amount of water creating more bubbles until eventually you have a giant mess and a pump that is only good for a paperweight now. 

 

[Blob-79]

one thing you could do is kinda half and half, use your big pump in the sump, divert a little to where you would normally want the water to start off in the sump, the rest dump into the return pump section of the sump and ....voila! closed loop without the "closed" in it

 

[Cal_stir]

your 55 is probably tempered so drilling is out, you can use an aqualifter pump to ensure no loss of siphon, make sure the aqualifter is plugged into the same outlet  as return pump, the protien skimmer will work the same in a high flow sump as a low flow sump.
the more flow across live rock the better, once you have it tuned in it will stay there, you can get a leak monitor that will sense if the floor is wet and shut down your pump, there are a lot of people using overflows successfully, yes, some have had floods, but with the aqualifter pump it is rare.