To run a closed loop or not?

[PPBlimpy]

I just picked up my 300G acrylic tank for my next build with a ton of extras.

Will be a mixed reef - with some SPS

Tank is 96 x 30 and 24 tall for reference with 2 center overflow boxes. approx 1 foot separating , plumbing goes out the back

Trying to come up with an idea for flow- closed loop or powerheads
With the tank came 3 NIB Leopard L160 external pumps rated at 4200 GPH
I also have an assortment of gyre style pumps i could use.

If I go closed loop
Thinking 2" input between the two overflows
2x 1.5inch return into the tank low on the back wall or maybe a 2" in the middle below the input and can reduce inside the tank to 4 x 1" lines.

any thoughts would be appreciated.

 

[JumboShrimp]

Sounds like a cool project-- go for it!

 

[PPBlimpy]

input and returns thru the back or the bottom?

 

[PPBlimpy]

Decided run the closed loop, going to make a wave device similar to a OM4.

Perk of being a machinist I guess.

 

[mfinn]

I have a closed loop on my 240. It's powered by a Red Dragon 150 watt pump.
I have a 2" suction about 10" off the bottom on the back wall near the center.
I have 4 returns going through the back wall, 2 up high and 2 down low.
On the inside I have a 3/4" Y going to two1/2" fan nozzles on each inlet with water going in 8 directions.
I actually have a couple mp40's on this tank too.
I've read where people say this old outdated technology, but if it still works, why not?

 

[PPBlimpy]

This sounds similar to the layout I am looking to do. 2” Suction will be center of tank up between the overflows. 4 1.5”returns- possibly thru the bottom in 4 corners- plan is to run a DIY ocean motions type diverter valve. Once thru the bottom they will come up and T 2 x 1” lock lines with RFG nozzles that I can point.

I am also running 2 12000lph return pumps out of the sump. Each will T at the top of the tank and drop in the top with RFG nozzles or fans, unsure of which yet

 

[areefer01]

I've read where people say this old outdated technology, but if it still works, why not?

Ignorance is bliss. Well, and a pinch (er, dump) of marketing. The only challenge in my opinion is planning. Can be a bit tricky to visualize but if one takes the time I personally feel it is more rewarding and ascetically pleasing.

 

[PPBlimpy]

I planned on building this tank just like my last 8’ tank 20 years ago. Was going to run 4 x250 halides, standard closed loop,all analog times etc.

things have changed, found a good deal on 4 noopsyche lights. And decided to make my own OM4. Have skins 3 leopard l160 4400gph pumps sitting here new in box, might as well use 1

 

[italquam]

I have a closed loop on my 240. It's powered by a Red Dragon 150 watt pump.
I have a 2" suction about 10" off the bottom on the back wall near the center.
I have 4 returns going through the back wall, 2 up high and 2 down low.
On the inside I have a 3/4" Y going to two1/2" fan nozzles on each inlet with water going in 8 directions.
I actually have a couple mp40's on this tank too.
I've read where people say this old outdated technology, but if it still works, why not?

Which technology is outdated

 

[mfinn]

Which technology is outdated

I'm not sure what your question is.

 

[italquam]

I'm not sure what your question is.

Hello, just when you mentioned people say it is old outdated technology? Did you mean closed loop systems?

 

[PPBlimpy]

I have seen where a lot of people mention a AC pump driven closed loop as being out dated technology in the reef keeping world.

I have decided to not only do the closed loop but am building my own 4 way rotating wave valve. 1” pvc to each corner of the tank. Once thru the bottom of the tank the outlets will split to 2 x 3/4 RFG nozzles on loc line.

Also both 1” return lines will come up and over the back wall and split to two output with each with a single 3/4 RFG nozzles.

In the end it will be 12 3/4 RFG nozzles 8 of which will be alternating 4 will be constant flow.

Hoping this will provide enough flow to not need power heads in the tank.

Closed loop will be feed by a 4400 gph pump
Returns are 2 3170 gph dc pumps- figuring 40% loss for head height.

 

[mfinn]

Hello, just when you mentioned people say it is old outdated technology? Did you mean closed loop systems?

I've read in threads where people will say that the closed loop is outdated and there are better options.
I disagree. I use one on my 240 and would not change it.

 

[ca1ore]

I have seen where a lot of people mention a AC pump driven closed loop as being out dated technology in the reef keeping world.

Closed loop is certainly not as popular now as it was, say, 20-years ago; having been largely replaced by in tank circulation devices like the vortech. I ran one (with the OM4) on my last big tank, and it worked fine. One thing I never did was to run either suction or returns through the bottom of the tank. If you have any problems with leaks, the entire volume of the tank is available to soak your floors/carpets. No thanks! Much better, in my view, to run both from a point high up in the tank. Makes very little difference to in-tank flow and is inherently safer.

 

[OrionN]

I used close loops back in 2000 for my 420 gal tank. Powers by two dolphin 1 amp pumps. You must defuse the intake because this is high flow area and will purée anything get into it. Screen to keep snails out because a hard snail shells (the tiny hard shell Strombus are big offender) can really rune a propeller.
I have an automated 3 ways valve to divert the flow from one side to the other. Still have it if you interested to get from me.

 

[PPBlimpy]

Closed loop is certainly not as popular now as it was, say, 20-years ago; having been largely replaced by in tank circulation devices like the vortech. I ran one (with the OM4) on my last big tank, and it worked fine. One thing I never did was to run either suction or returns through the bottom of the tank. If you have any problems with leaks, the entire volume of the tank is available to soak your floors/carpets. No thanks! Much better, in my view, to run both from a point high up in the tank. Makes very little difference to in-tank flow and is inherently safer.

This is true and may reconsider hole placement but have ran thru the bottom on previous tanks.

The last acrylic tank I did a closed loop on I actually took 1” x5”x5” acrylic squares and drilled/tapped 1” npt and then used weldon3 to glue them to both sides of the bottom of the tank. Essentially forming my own permanent bulk head. Worked well and never leaked.

I don’t want to see much plumbing in the tank or power cords and powerhead

 

[PPBlimpy]

I used close loops back in 2000 for my 420 gal tank. Powers by two dolphin 1 amp pumps. You must defuse the intake because this is high flow area and will purée anything get into it. Screen to keep snails out because a hard snail shells (the tiny hard shell Strombus are big offender) can really rune a propeller.

I will be running a 4x4x4 black basket over the intake. Will glue rails on so I can slide the basket off easily for cleaning. Will also have an input screen directly on the bulkhead.

 

[PPBlimpy]

I used close loops back in 2000 for my 420 gal tank. Powers by two dolphin 1 amp pumps. You must defuse the intake because this is high flow area and will purée anything get into it. Screen to keep snails out because a hard snail shells (the tiny hard shell Strombus are big offender) can really rune a propeller.
I have an automated 3 ways valve to divert the flow from one side to the other. Still have it if you interested to get from me.

i appreciate the head up!

 

[mfinn]

Closed loop is certainly not as popular now as it was, say, 20-years ago; having been largely replaced by in tank circulation devices like the vortech. I ran one (with the OM4) on my last big tank, and it worked fine. One thing I never did was to run either suction or returns through the bottom of the tank. If you have any problems with leaks, the entire volume of the tank is available to soak your floors/carpets. No thanks! Much better, in my view, to run both from a point high up in the tank. Makes very little difference to in-tank flow and is inherently safer.

I've done both ways. Never thought too much about it until a buddies 350 gallon tank that was bottom drilled gave out. The whole bottom fractured from the suction hole drilled right in the center ( IMO the worst place possible).

 

[mfinn]

I will be running a 4x4x4 black basket over the intake. Will glue rails on so I can slide the basket off easily for cleaning. Will also have an input screen directly on the bulkhead.

On my current tank, the suction hole is drilled about a third of the way up the back wall. I have a pvc tee with 2 10" lengths of pipe going in each direction with caps on the inside. I drilled countless holes in each side.
Over the top of that I made a 14" long x 10" wide strainer box. I can reach the box from the top of the tank and be able to clean it off.