CLOSED LOOP PUMP

[TaylorPilot]

I wonder how many people here have actually used a CL? There is no head loss on a CL - they are closed systems. There is friction and pipe loss. I cannot believe that people are suggesting DC pumps. DC pumps are a joke on a CL unless they are powerful like a Abyzz. They only move the advertised water with no restrictions whatsoever and they slow down significantly with any type of back pressure. There is no way around this.

Suggesting DC pumps for a CL (there are a few at $1000+ price point) is almost as ridiculous as suggesting DC pumps for 30 foot head applications - you are going to end up with a AmpMaster (or the like) or else you will be unhappy, just like high head people end up with Iwaki or PanWorld or else they are unhappy.

I used to use spa flex for CLs to cut down on friction and elbows and stuff. Don't forget your unions near the pump so that you can take it out if you ever need to. Eductors can provide lots of flow if you have a strong pump - they are amazingly effective if you have velocity out of the nozzle. If you want 4 outlets and don't have the flow to keep the velocity strong, then look at an Ocean's Motion 4 way.

If you don't want to pay for a strong AC pump, then get some gyres and in-tank pumps and save yourself some trouble.

If you really want to go crazy, buy the wetside from MRC or Dolphin, and order a 3 phase motor block and hook it up to a VFD....you can make as large a controllable pump as you want. You can get NEMA rated VFDs that are industrial quality and most have 0-10v inputs for control to hook up to aquarium controllers...some of the nice ones are sine wave VFDs, so you can probably make them quieter than standard motors...none of them are quiet though...I think that is the primary reason for suggesting a DC pump...I have never used an OceansMotions, but back in the day I remember hearing people having issues with them binding up when they got some buildup in them...

 

[TaylorPilot]

Hey @jda - I've been considering a closed loop system for my 6ft peninsula.... Mulling around the idea of 2 x Vectra L2s mounted to the back overflow pane (on 12 hr alternation). I know the DC pumps are wimpy, but take a gander at this article, and let me know your thoughts on this setup with large eductors...

The Quest for Ludicrous Aquarium Water Flow | Reef Builders | The Reef and Saltwater Aquarium Blog

My path in the larger reef aquarium world began with college studies of the interaction between light and water flow, culminating in a water movement pattern that I introduced as ‘Gyre Flow’.

reefbuilders.com

Those things are a foot long...might as well stick a trolling motor in your tank...I would love to test one out though...I promise you that 1500 GPH number he gave is a guestimate at best...I just bought a pretty nice industrial 2" flow meter and an L2 to test out some of my overflow designs...I was planning on getting a larger dolphin pump to test out some of the custom larger models (60" weir with 2" drains). I would be really interested to see how much that eductor cuts down on flow...I remember years ago on RC there was a thread about them...Basically they said if you got a super high pressure pump to operate them that they could put out some flow, but the idea was not in power or noise savings...it was about not having a ton of 2" bulkheads and plumbing pouring out into your tank...a few high pressure 1" lines with small eductors would put out a lot of flow, but it used a lot of power and put out a lot of noise...I even remember they were using another version of the oceansmotions that had a stepper motor attached to it, so you could tweak the speed and order of how they rotated. Oceansmotions has different sets of cams you can buy where it will do them in different sequences, or have it either do 1 or 2 lines at a time...they setup a tank and would inject air right before the outlet of the eductor to show how the flow was compared with different systems and layouts...it was pretty interesting..I did a quick search and couldn't find it, but this was atleast 10 years ago...

 

[BOWHUNTER4250]

Hey @jda - I've been considering a closed loop system for my 6ft peninsula.... Mulling around the idea of 2 x Vectra L2s mounted to the back overflow pane (on 12 hr alternation). I know the DC pumps are wimpy, but take a gander at this article, and let me know your thoughts on this setup with large eductors...

The Quest for Ludicrous Aquarium Water Flow | Reef Builders | The Reef and Saltwater Aquarium Blog

My path in the larger reef aquarium world began with college studies of the interaction between light and water flow, culminating in a water movement pattern that I introduced as ‘Gyre Flow’.

reefbuilders.com

WOW !! That was some serious water flow !! does make you want to consider the Vectra pumps ?

 

[Katrina71]

@JoshH this might be up your alley

 

[Fish man]

One of the major factors in our pumps flow rates is the proper size of pipe.

I have a Varios 8 Rated at 2700 gallons.
I started with a 1 inch return line with a head height at 5 feet a 90 and two 45s.
My flow rate was 800 gph.
Swapped it for 1-1/2 that the pump was designed for an my GPH went up to 1380.
So close to a 600gph difference.

Agreed. I would look at pipe size. Especially if you're getting cavitation. Is it overly noisy? Does the pump sound like it has air in it? These are signs of cavitation. That pump could be starved for water. You can only push/pull so much water through a given size pipe. 3/4 inch pipe maximum velocity is 1410gph. 1" is 2220gph. That's without any head loss. 1 1/4" at 3700gph is the minimum recommended. Throwing a bigger pump on or increasing back pressure won't solve your issue. Like Snoopy 67 said, you want to reduce pressure. Maybe replumb in 1/12" first on both inlet and outlet side. Much cheaper then buying a bigger pump only to find out it only makes your situation worse. Then after replumbing if you find you need more flow you'll have the plumbing to support a bigger pump.

 

[BOWHUNTER4250]

Agreed. I would look at pipe size. Especially if you're getting cavitation. Is it overly noisy? Does the pump sound like it has air in it? These are signs of cavitation. That pump could be starved for water. You can only push/pull so much water through a given size pipe. 3/4 inch pipe maximum velocity is 1410gph. 1" is 2220gph. That's without any head loss. 1 1/4" at 3700gph is the minimum recommended. Throwing a bigger pump on or increasing back pressure won't solve your issue. Like Snoopy 67 said, you want to reduce pressure. Maybe replumb in 1/12" first on both inlet and outlet side. Much cheaper then buying a bigger pump only to find out it only makes your situation worse. Then after replumbing if you find you need more flow you'll have the plumbing to support a bigger pump.

Very good point , and that was my thought exactly ! i will take this apart , re plumb with 1-1/2 inlet and outlet with 45's and do this on only one side ( 2 " Y " loc-lines ) with the one pump i currently have .... IF this gives me enough flow to where im happy with it i can buy another pump like i have and do the other side , if it is too much for one side i can split it again and reduce it but im thinking one pump on each side with 1-1/2 " inlet/outlet will give me at least better than i have now ! Im not looking for massive amount but enough to keep detritus from settling ( dead spots )

 

[naterealbig]

WOW !! That was some serious water flow !! does make you want to consider the Vectra pumps ?

Well I'm not going by any numbers that are thrown out in the video. Like was mentioned before, calling it a "guestimate" is being nice. Watching the video though, there is clearly a large amount of water movement. Is it more than the pumps would move without the eductors? That's the real question.....

 

[Shooter6]

Get the jebao dcp20000. Im sure that will have plenty of flow. Im doing the same, closed loop on a 400g and 320g. I am considering the dcq10000, or moe of the dcp20000.
Im looking at using 2 pumps per tank with 4 retun nozzles for each, with rfg nozzles.
I think that is part of your problem, to many exit points (8) reducing the pressure to each. If you closed half of those off each remaining will have an increase in pressure.
Im considering the dcq because of the wVe function, but the dcp20000 has massive power.

 

[Shooter6]

I do not consider anything that Reef Builders says to be either objective or accurate, although it is not necessarily inaccurate - if you pay him and advertise with them, they will love on your stuff.

Eductors are the real deal if you can get some velocity going through them.

For your situation, how about a 1" sea swirl with an eductor and a single pump that can power through?

He has a vid showing results, not just typing an opinion with nothing showing the results .

 

[Shooter6]

For the op, is the dcq you have the same size as the dcq10000? I know theres a smaller size and a larger size. I have a dcq10000. Its pretty small. Have you considered putting it in the overflow box at the bottom, and plumb the returns from there? Or put them external, under the tank or behind it on a shelf, so zero head pressure to combat?

 

[BOWHUNTER4250]

For the op, is the dcq you have the same size as the dcq10000? I know theres a smaller size and a larger size. I have a dcq10000. Its pretty small. Have you considered putting it in the overflow box at the bottom, and plumb the returns from there? Or put them external, under the tank or behind it on a shelf, so zero head pressure to combat?

I believe the one i have is the same size or slightly smaller , i have the DCQ8000 and i bought this because of the same thing , the wave mode ... i currently have the pump behind the tank and on a shelf directly under the tank , no way this will fit in any overflow box unless it is one large box to accommodate return plumbing and a pump ....... My Son is plumbing a 180 and he is using the DCP20000 , im curious to see the water movement with that ?? i will take this apart and open the plumbing up to the max the pump will allow , run this on one side only and see what happens ..... IF it gives me what im looking for i will get another pump and do the same to the other side ??
I was running a WP40 on pulse mode on the back at each end of the tank and this worked well for water movement , the problem with that is they need to be cleaned often and as coral grows it will be harder to get them out ... Hence the reason for the closed loop design .

 

[Shooter6]

I believe the one i have is the same size or slightly smaller , i have the DCQ8000 and i bought this because of the same thing , the wave mode ... i currently have the pump behind the tank and on a shelf directly under the tank , no way this will fit in any overflow box unless it is one large box to accommodate return plumbing and a pump ....... My Son is plumbing a 180 and he is using the DCP20000 , im curious to see the water movement with that ?? i will take this apart and open the plumbing up to the max the pump will allow , run this on one side only and see what happens ..... IF it gives me what im looking for i will get another pump and do the same to the other side ??
I was running a WP40 on pulse mode on the back at each end of the tank and this worked well for water movement , the problem with that is they need to be cleaned often and as coral grows it will be harder to get them out ... Hence the reason for the closed loop design .

I believe splitting the returns, into 2 sides, or in half but each doing part of both sides is the way to go. Every retun exit ruduces the pressure by half, squared by the total exits.
I amd doing the sMe thing for the same reason on these tanks. Ill probably still run gyres at the but want the least amount of cords going into the tank as possible

 

[BOWHUNTER4250]

I believe splitting the returns, into 2 sides, or in half but each doing part of both sides is the way to go. Every retun exit ruduces the pressure by half, squared by the total exits.
I amd doing the sMe thing for the same reason on these tanks. Ill probably still run gyres at the but want the least amount of cords going into the tank as possible

I will update this thread once i re do the plumbing on this , i do still have a MP40 on each side of my tank with 4 return lines that all have a " Y " loc-line , however im running a REEFLO Hammerhead pump for just these . And yes i dont want the cords and the maintenance of Gyre's or power heads , i want the corals to grow around these lines eventually

 

[Shooter6]

Consider replacing the y ( duckbill) outlets withvthe random flow generator ones.

Random Flow Generators for Loc-Line

Attaches to 1/2", 3/4" Loc-Line and creates random flow patterns. Vivid Creative Aquatics 3D printed random flow generators easily snap onto standard Loc-Line segments for a custom flow pattern through their patent pending randomized design. Each RFG is made of reef-safe PETG plastic and made to...

www.bulkreefsupply.com

These really aid in changing currents. Ive not tested them with the dcq on pulse, but i have 4 of these running off my dcp20000 return pump. On my 180g.

 

[BOWHUNTER4250]

Consider replacing the y ( duckbill) outlets withvthe random flow generator ones.

Random Flow Generators for Loc-Line

Attaches to 1/2", 3/4" Loc-Line and creates random flow patterns. Vivid Creative Aquatics 3D printed random flow generators easily snap onto standard Loc-Line segments for a custom flow pattern through their patent pending randomized design. Each RFG is made of reef-safe PETG plastic and made to...

www.bulkreefsupply.com

These really aid in changing currents. Ive not tested them with the dcq on pulse, but i have 4 of these running off my dcp20000 return pump. On my 180g.

I Have those on all of my return lines now and the set up i just made !