Tank/Sump Flow Through Rates & Closed Loop Systems

[Reefn'_Dude]

Hello All,


I am working on setting up my second reef tank (slowly but surely, thinking out every aspect so I can have piece of mind when finished).


I am trying to decide on one of the following 2 scenarios for my main tank flow/sump return setups.


Please provide any input, suggestions and feedback as to why you may think one setup is better than the other.


First, a brief summary of how the tank is set up:

- 75 Gallon All Glass Display, corner baffled and durso drained via 1-1/2" plumbing
- 175W MH 14,000K lighting with 140W supplemental Flouros and moonlights.
- Supplementing power heads in tank will be one Kyrolla Nano and a Kyrolla 2
- The tank has a 35 gallon sump... The right side of the sump is a 12 gallon refugium fed at ~250GPH from the main display through a MarineLand 360 canister filter.
- The sump has mechanical and biological filtration including pads, LR, bubble traps and Protien skimming.



OK so I have 2 pumps, a Quiet one 3000 and Quiet one 6000 to work with. One will be used in a closed loop 1" SCWD system creating wave motion in the tank, the other will be my return.


OPTION 1:


Use the 6000 in the CL system creating ~931GPH through the display tank.

Use the 3000 as the return pump, turning ~545GPH through my sump

ADVANTAGES:

- Heavy switching of the SQWD in this configuration with a 120 second swapping time
- Vigorous water movement in the display, allowing for longer detritus and waste suspension times.
- Super happy fish playing in the currents.
- Total water volume turnover about 12X per hour

DISADVANTAGES:

- Sump flow through is at about 5x per hour, less than the optimal 7x-10x
- are there more?



OPTION 2:

Use the 3000 in the CL system creating ~549GPH through the display tank.

Use the 6000 as the return pump, turning ~928GPH through my sump


ADVANTAGES:

- optimal flow through in the sump at 8.8x Per hour



DISADVANTAGES:

- Reduced SCWD flow rate means longer switching time and lower output efficiency
- 14X total tank volume turn over per hour is a bit high I think...




I have had great success with the Closed Loop SCWD system in the past but it is clear that the new 1" model is designed for the higher flow rates and works best with them.




Please let me know what you guys think!!!

 

[Grym]

1ââ"šÂ¬Ã‚ SCWD will run with pump applications from 500 GPH to 3500 GPH
I'd use the bigger pump you can always throttle it down. Is the second pump going to be a second closed loop through the refugium and back to the sump?

 

[Reefn'_Dude]

The other pump will be for returning water from the sump to the display, I guess that is considered a closed loop as well huh?

 

[Reefolution]

Closed loop is where your water intake is drawing from the same body of water that it pumps back into. A situation where there is no "static head" that the pump has to work against. Pumping from your sump back up to your display tank has a static head which is the difference between the water surface of the sump to the water surface of the display.

 

[kgross]

Use the 6000 for the closed loop and the 3000 for sump return.

You do not need 7 to 10 times tank volume per hour through the sump.

Kim

 

[das75]

Still really don't know where the 7-10X through a sump is optimal comes from.

Can somewhat agree with a comment "more than the skimmers rated gph isn't necessary", but can't see anything wrong with the return pump adding to the overall flow in the display.

With a different pump, was running 2000gph through a 75g sump without problems (no micro-bubbles, still had detritus settling). Maybe the skimmer wasn't getting all the stuff out during the first turnover but had a continuous raw water supply to draw from.

If you say the SCWD performs with a higher flow, go for it, but way too many variables in this hobby to sweat numbers or ratios too much.

If you like numbers though, check this Canreef thread on display turn over, a huge range.