Determining sump flow and matching skimmers

[ShinerMaginer]

I'm trying to determine if the flow through my planned sump is appropriate. I'm building a 200DD, which will have 2 drains and 2 returns. So, roughly 1200-1300 gph draining through 2 x 1" overflows, give or take depending on set up. I'm planning for my sump to hold about 52g at normal operating times (total volume is 90g so lots of room). This is where my history of falling asleep in math class comes back to haunt me!

I don't fully understand how to match my sump to my skimmer output. I'm looking at a SRO3000 which lists a "water circulation" rating of 425gph. How does this relate to flow through my sump?

 

[Reefing Madness]

1" drains can handle 960gph
You want your skimmer to be able to handle 2 times your total water volume. Not matching any sump rating. Figuring your DT is 200g + your 52g normal operating volume in your sump, would make your system at 252g total volume, you should be looking at roughly a 400g skimmer, of which the SRO3000 is only rated for a 300g tank. Might want to look bigger.
Or
Your sump will be used as a Fuge
Or
Your going to be running an ATS- Alage Turf Scrubber

 

[ShinerMaginer]

The sticker on the tank from the manufacturer said 700g? The 52g includes a section of my sump for a fuge, but I'm planning on plumbing my frag tank into the system too. It's relatively small. I've read all these comments about matching the flow through the sump to the output of the skimmer, which I couldn't understand.

 

[Reefing Madness]

Your tank is 700g? I only come up with 201g for your tank.
Is your mearuement 48x36x27?
http://reef.diesyst.com/volcalc/volcalc.html

 

[ShinerMaginer]

No I meant 700gph drain through each 1" bulkhead, so those were the numbers I've been working with.

 

[ShinerMaginer]

And yeah, those are the right dimensions.

 

[Reefing Madness]

Here is actual numbers on PVC Drains
#1 FlexPVC®.com PVC presents GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6"

1/2"	.50-.60"	.85"
3/4"	.75-.85"	1.06"
1"	1.00-1.03"	1.33"
1.25"	1.25-1.36"	1.67"
1.5"	1.50-1.60"	1.90"
2"	1.95-2.05"	2.38"

[TD="align: center"]Sch 40 Pipe Size[/TD]
[TD="align: center"]ID
(range)[/TD]
[TD="align: center"]OD[/TD]
[TD="bgcolor: #80FF80, align: center"] GPM [SIZE=-2]
(with minimal pressure loss & noise)[/SIZE][/TD]
[TD="bgcolor: #80FF80, align: center"] GPH [SIZE=-2]
(with minimal pressure loss & noise)[/SIZE][/TD]
[TD="bgcolor: #FFFF00, align: center"] GPM [SIZE=-2]
(with minimal pressure loss & noise)[/SIZE][/TD]
[TD="bgcolor: #FFFF00, align: center"] GPH [SIZE=-2]
(with minimal pressure loss & noise)[/SIZE][/TD]
[TD="bgcolor: #FF4343, align: center"] GPM [SIZE=-2]
(with significant pressure loss & noise)[/SIZE][/TD]
[TD="bgcolor: #FF4343, align: center"] GPH [SIZE=-2]
(with significant pressure loss & noise)[/SIZE][/TD]

[TD="bgcolor: #80FF80"]7 gpm[/TD]
[TD="bgcolor: #80FF80"]420 gph[/TD]
[TD="bgcolor: #FFFF00"]14 gpm[/TD]
[TD="bgcolor: #FFFF00"]840 gph[/TD]
[TD="bgcolor: #FF4343"]21 gpm[/TD]
[TD="bgcolor: #FF4343"]1,260 gph[/TD]

[TD="bgcolor: #80FF80"]11 gpm[/TD]
[TD="bgcolor: #80FF80"]660 gph[/TD]
[TD="bgcolor: #FFFF00"]23 gpm[/TD]
[TD="bgcolor: #FFFF00"]1,410 gph[/TD]
[TD="bgcolor: #FF4343"]36 gpm[/TD]
[TD="bgcolor: #FF4343"]2,160 gph[/TD]

[TD="bgcolor: #80FF80"]16 gpm[/TD]
[TD="bgcolor: #80FF80"]960 gph[/TD]
[TD="bgcolor: #FFFF00"]37 gpm[/TD]
[TD="bgcolor: #FFFF00"]2,220 gph[/TD]
[TD="bgcolor: #FF4343"]58 gpm[/TD]
[TD="bgcolor: #FF4343"]3,510 gph[/TD]

[TD="bgcolor: #80FF80"]25 gpm[/TD]
[TD="bgcolor: #80FF80"]1,500 gph[/TD]
[TD="bgcolor: #FFFF00"]62 gpm[/TD]
[TD="bgcolor: #FFFF00"]3,750 gph[/TD]
[TD="bgcolor: #FF4343"]100 gpm[/TD]
[TD="bgcolor: #FF4343"]5,940 gph[/TD]

[TD="bgcolor: #80FF80"]35 gpm[/TD]
[TD="bgcolor: #80FF80"]2100 gph[/TD]
[TD="bgcolor: #FFFF00"]81 gpm[/TD]
[TD="bgcolor: #FFFF00"]4,830 gph[/TD]
[TD="bgcolor: #FF4343"]126 gpm[/TD]
[TD="bgcolor: #FF4343"]7,560 gph[/TD]

[TD="bgcolor: #80FF80"]55 gpm[/TD]
[TD="bgcolor: #80FF80"]3300 gph[/TD]
[TD="bgcolor: #FFFF00"]127 gpm[/TD]
[TD="bgcolor: #FFFF00"]7,650 gph[/TD]
[TD="bgcolor: #FF4343"]200 gpm[/TD]
[TD="bgcolor: #FF4343"]12,000 gph[/TD]

 

[ShinerMaginer]

Thanks, this is very helpful! I have always been planning on using a submersible return pump, because I didn't want to drill the tank I have for a sump. Obviously this limits my options. Is there any sense in using the 3/4 bulkhead for the drain, and then using the 1" for the return? I ask because the head loss calculation for my setup using the 3/4 as a return doesn't get me high enough to keep up with the drain. If I switch it around, I would be ok, and would still have enough pressure to run a manifold. Not sure if this makes any sense. I guess the other option is drilling the tank I have for the sump, or scrapping it and going a different direction for the sump.

 

[Reefing Madness]

Better using the 1" for drains, and the 3/4 for return. The returns can handle pumps pushing water, your drains are just using gravity, and you want the most out of them. You don't have to drill, although you'd sleep better at night knowing that a flood wouldnt' be happening.

 

[ShinerMaginer]

To be honest, the more I think about this set up, the more I realize I need to rethink the way I have the sump set up. I don't think a submersible return pump is the way to go for this tank. It was ok for my 40 and 65g, but I think I will need to redo the sump to accommodate an external return pump.

 

[Reefing Madness]

Nohing wrong at all using a submersible pump. I used one myself when I had mine set up. Beats drilling for the pump.

 

[ShinerMaginer]

I had a look at a Head Loss Calculator, and using a Mag 24 plumbed down to 3/4 to fit the return, I wouldn't have enough return gph to get the job done. Don't get me wrong, I would much rather use a submersible for the setup that I've been thinking about. Other than the Danner pumps, can you recommend something? What did you use?

 

[Reefing Madness]

I used an old Quiet One Pump 4000, I only had a 900gph overflow. You don't need to match the drains exactly, but close is good.
That MAG drive will still pump 1630gph at 5', nothing wrong with that number.

 

[ShinerMaginer]

I figured it would be close enough too. But the head loss calculator I used showed with 2 return outlets and a general rough outline of the plumbing setup, the return flow would be closer to 1100gph, which isn't enough to keep up with the drain? Not sure how accurate the calculator on Reef Central was, but it's all I could find.

 

[DaveMorris]

As mentioned above, your skimmer size has absolutely nothing to do with flow through your sump. Unless you are using a gravity fed skimmer and have all of the water flowing through the skimmer. In a typical sump set up where the drains feed "dirty" water into a return chamber, most people put the skimmer in this chamber. In this configuration you have no way of directing all of the dirty water through your skimmer. A lot of that water will flow right passed the skimmer and never enter the skimmer intake. Skimmer size is dependent on total water volume and I agree with the above statement that your skimmer should be rated for twice what your water volume is. Ratings vary considerably from manufacturer to manufacturer though so there is still a little guess work involved.

 

[lemonyx]

I have always used an external pump, mostly to help keep the heat out of the water and not have to go the route of a chiller. The reefflo pumps are ideal for this, the Dart/Snapper hybrid would be ideal for your set up and you can add a valve on the output side to keep up with the drains.

IMO, would use a bigger sump with a higher "overhead" since you will be connecting a frag tank to this sump. So something like a 48x24x16-18 tall with no more than 9" high for the tallest baffle , this will give you about 44gals working volume and about 35gals overhead - which is for when you turn off the return pump and all the water drains back to the sump



This one I build for a friend for his 312 gal DT and he uses a Hammerhead pump for a return. The sump is 50" x 30" x 16" tall and built to "flow"

gl

 

[Reefing Madness]

I figured it would be close enough too. But the head loss calculator I used showed with 2 return outlets and a general rough outline of the plumbing setup, the return flow would be closer to 1100gph, which isn't enough to keep up with the drain? Not sure how accurate the calculator on Reef Central was, but it's all I could find.

At this point your drains will be waiting on, or running only at the speedin which your returns will give it back. Won't hurt a thing. It says that the Drains will handle up to 900gph, doesn't have to been set at that number.

 

[ShinerMaginer]

I have always used an external pump, mostly to help keep the heat out of the water and not have to go the route of a chiller. The reefflo pumps are ideal for this, the Dart/Snapper hybrid would be ideal for your set up and you can add a valve on the output side to keep up with the drains.

IMO, would use a bigger sump with a higher "overhead" since you will be connecting a frag tank to this sump. So something like a 48x24x16-18 tall with no more than 9" high for the tallest baffle , this will give you about 44gals working volume and about 35gals overhead - which is for when you turn off the return pump and all the water drains back to the sump



This one I build for a friend for his 312 gal DT and he uses a Hammerhead pump for a return. The sump is 50" x 30" x 16" tall and built to "flow"

gl

Lemonyx - thanks for this pics. This is the other route I've considered. What is the layout of this sump?

 

[hart24601]

I agree that you don't need to link skimmer flow to sump flow. I am hesitant to recommend the 2x rated volume thing though. Companies rate their skimmers drastically differently with some being spot on and others being much much more liberal. Take a look at the body size, flow rate and most important I think is the air flow rate and if it's adjustable.

I have always found it was better to size the skimmer 5-10x the size of the system in air-flow. So for 250g between 1250-2500 L/hr air flow. Take vertex, their ratings are pretty spot on imo. The 200i is rated to 225 gallon tank from the factory and has 1800-2000 l/hr and I wouldn't hesitate to use it on this system.

Look at that rating vs aquamaxx (still good skimmers but waaay overrated for tank size by the company)

Aquamaxx says their CO1 is rated to 175g and flows 360 L/hr air. Their CO2 they rate to 350 gallons and it flows 720 L/hr airflow.

Some drastic differences between manufacturers, so don't get caught up in the tank rating, but look at the stats.

 

[ShinerMaginer]

I agree that you don't need to link skimmer flow to sump flow. I am hesitant to recommend the 2x rated volume thing though. Companies rate their skimmers drastically differently with some being spot on and others being much much more liberal. Take a look at the body size, flow rate and most important I think is the air flow rate and if it's adjustable.

I have always found it was better to size the skimmer 5-10x the size of the system in air-flow. So for 250g between 1250-2500 L/hr air flow. Take vertex, their ratings are pretty spot on imo. The 200i is rated to 225 gallon tank from the factory and has 1800-2000 l/hr and I wouldn't hesitate to use it on this system.

Look at that rating vs aquamaxx (still good skimmers but waaay overrated for tank size by the company)

Aquamaxx says their CO1 is rated to 175g and flows 360 L/hr air. Their CO2 they rate to 350 gallons and it flows 720 L/hr airflow.

Some drastic differences between manufacturers, so don't get caught up in the tank rating, but look at the stats.

Thanks hart24601! I have been researching skimmers and wasn't sure how to interpret the air draw ratings. To your point the SRO3000 might be ok water volume wise if my tank stays light-medium stocked, but its vastly underpowered from an air draw perspective. I'll give that some more thought.