Poll: Sump size?

dbl · Mar 2, 2018

An often asked question is "what size sump would be best" for my new "X" gallon tank? The typical answer is the bigger the better - more total water volume in the system. Honestly, it's how I would answer the question. But I'm curious if there is a more precise answer? Is there an ideal percentage of display size for the sump? Is there a minimum size for a sump? Or is it truly just to put the largest sump that will fit in your stand?

So let's here your philosophy on the proper answer.

sebastiaan1985 · Mar 2, 2018

Interesting to follow, since I am in the market for a new sump.

Am planning on buying the biggest sump possible, so I can use it for a future build as well.

Current DT: 140L
Current sump: 72L

Planned sump: 220L

vlangel · Mar 2, 2018

I too always said as big as possible until I had the display tank overflow when the glue gave out on my hob overflow box and the back portion dropped down breaking the syphon.

I know most of you do not use hob overflow boxes and most of you have more than 1 standpipe so a mishap is minimized. (Actually that has been my only mishap in 10+ years and luckily I only had a 10 gallon sump at the time so only a couple gallons went on the living room floor). Still, anything is possible.

Now I have a 20 gallon sump for a 56 gallon tank. The sump probably holds 13 gallons of water with rock, sand and equipment displacement, but the return pump would probably run dry after 4 gallons, maybe less. That would be a mess but not not an all out disaster.

I have thought about using a 40B but never have because of the flood possibility. I guess if I built the return chamber small enough I could minimize the damage.

madweazl · Mar 2, 2018

By empty capacity, my sump is 36% of the displays volume (75g) and by actual volume, it holds 27% (normal operating conditions). I've always tried to stick with 25-30% as a rule because components (skimmers, refugiums, pump, heaters, etc.) grow in size with the display but that gets increasingly difficult as the display grows. I havent ordered the sump for our 150g yet but I'm planning on using a 50g long.

five.five-six · Mar 2, 2018

Return flow is the most expensive flow in your tank in terms of pump cost, electrical cost and heat. Also, the higher the return pump rate, the lower you have to keep your sump level to avoid overflow in the case of power outage.

I have a 135 with a 40 gal sump and use a tunze 1073.050. At 5’ of head it makes about 500 GPH which is plenty

SEMA · Mar 2, 2018

If you had to put a number on it, I would say around 30% of size minimal. This applies to 0-180gal. Once you get bigger then 180, the % can go down a little.

Equipment choice and design factors dictate footprint of sump. You need enough volume for system shutdown/power off. If adding a refuge or live rock, I would go alot bigger.

If it's a normal everyday reef for a hobby, 30% works well because you can shut system down, fill sump with tank water, open a discharge valve off main pump hooked to hose out the door and boom your water change is half way done without bucketing.

madweazl · Mar 2, 2018

five.five-six said:
Return flow is the most expensive flow in your tank in terms of pump cost, electrical cost and heat. Also, the higher the return pump rate, the lower you have to keep your sump level to avoid overflow in the case of power outage.

I have a 135 with a 40 gal sump and use a tunze 1073.050. At 5’ of head it makes about 500 GPH which is plenty

My Snapper/Dart was cheaper than one of the four MP40s that are in the 150g. What does return rate have to do with sump water levels?

Reefin Dude · Mar 2, 2018

what is minimum, big enough to hold all of the back flow when the power goes off.

i will have a 45g sump on my 300g.

G~

SashimiTurtle · Mar 2, 2018

vlangel said:
I too always said as big as possible until I had the display tank overflow when the glue gave out on my hob overflow box and the back portion dropped down breaking the syphon.

I know most of you do not use hob overflow boxes and most of you have more than 1 standpipe so a mishap is minimized. (Actually that has been my only mishap in 10+ years and luckily I only had a 10 gallon sump at the time so only a couple gallons went on the living room floor). Still, anything is possible.

Now I have a 20 gallon sump for a 56 gallon tank. The sump probably holds 13 gallons of water with rock, sand and equipment displacement, but the return pump would probably run dry after 4 gallons, maybe less. That would be a mess but not not an all out disaster.

I have thought about using a 40B but never have because of the flood possibility. I guess if I built the return chamber small enough I could minimize the damage.

Using a HOB overflow is asking for a flood. Might as well bring the water hose inside and just let it run.

five.five-six · Mar 2, 2018

madweazl said:
My Snapper/Dart was cheaper than one of the four MP40s that are in the 150g. What does return rate have to do with sump water levels?

The faster the return rate the more water is in the DT, which means you need to leave more room in your sump in the event of a power outage. This is really easy to see with a DC pump, as you turn down the speed of a DC pump the level in the sump raises. The more GPH return you have, the higher the water level in the DT will be.

Snapper dart is about $300 for 2000 GPH @ 4’ of head works to 6GPH per dollar
MP40 is about $300 for 4500 GPH works to 15 GPH per dollar

MP40 is 4500GPH @ 38 watts works to 120GPH per watt
Snapper dart is 2000GPH @ 4’ of head @ 105 watts works to 20GPH per watt

Snapper dart is 2.5X as expensive in GPH as the MP40 up front and 6X as expensive in electrical costs.

I run halides, 500 watts for 5 hrs a day that’s 2.5KWH a day
Snapper dart uses 2.52KWH a day

Snapper dart is more expensive to run than halides.

madweazl · Mar 2, 2018

five.five-six said:
The faster the return rate the more water is in the DT, which means you need to leave more room in your sump in the event of a power outage. This is really easy to see with a DC pump, as you turn down the speed of a DC pump the level in the sump raises. The more GPH return you have, the higher the water level in the DT will be.

Snapper dart is about $300 for 2000 GPH @ 4’ of head works to 6GPH per dollar
MP40 is about $300 for 4500 GPH works to 15 GPH per dollar

MP40 is 4500GPH @ 38 watts works to 120GPH per watt
Snapper dart is 2000GPH @ 4’ of head @ 105 watts works to 20GPH per watt

Snapper dart is 2.5X as expensive in GPH as the MP40 up front and 6X as expensive in electrical costs.

I run halides, 500 watts for 5 hrs a day that’s 2.5KWH a day
Snapper dart uses 2.52KWH a day

Snapper dart is more expensive to run than halides.

The MP40s are $350 and there are four of them to create adequate flow within the display. Only one return pump is needed; additionally, when flow is reduced via a ball valve, power consumption is also reduced; I dont know by how much in this case. Comparing watts used to GPH produced doesn't work as it is a system, not a singular unit.

five.five-six · Mar 2, 2018

You can check it with a wattmeter. The flow you get from a return pump is far more expensive than flow from a circulation pump. It’s simple arithmetic.

Here is a helpful chart

If you need 4 MP40’s for adequate flow in a 150, you may want to look into tunze.

madweazl said:
The MP40s are $350 and there are four of them to create adequate flow within the display. Only one return pump is needed; additionally, when flow is reduced via a ball valve, power consumption is also reduced; I dont know by how much in this case. Comparing watts used to GPH produced doesn't work as it is a system, not a singular unit.

it

Reefsmoker · Mar 2, 2018

I've used bigger sumps in the past to increase total volume. Had a 40g rimless frag tanks that i ran a 40g sump in, kept the sump about half full so total water volume was about right at 60g. Also big sumps are AWESOME!

Greybeard · Mar 2, 2018

Minimum would be (A) big enough to hold the equipment you want to put in it, and (B) enough empty volume to contain whatever runs out of the tank when the power is out. The method and tools you're going to be using is going to have the biggest impact. A refugeum, if you're going that way, is probably going to be the biggest space concern. If you're doing Zeovit, well, you'll need space for the zeolite reactor and skimmer. Let function dictate form... when you're planning the system, figure out what you want, and then buy a sump that can hold it all. Better yet, buy a sump that can hold _more_ than you're planning... you're likely to find down the road that you want to add something to the sump.

The only reason to go small on a sump would be space restrictions... I had a 60g cube, 24" x 24" footprint. Knew from day one I wasn't going to have much space. Designed a stand that was 40" x 40", with an 8" shelf running all the way around the tank. Why? Space. Bigger sump, and more room for components outside the sump.

Maximum? If I could plumb my display into a nice clean bit of ocean, a couple miles offshore, maybe 20' down... that'd be just great. Be hard to do from the middle of Missouri, but no, I don't think there is such a thing as a maximum. Might have to make some special arrangements, if it gets way big...

I can envision a 40g tank over a 200g sump... the, what, 400gph? return pump would make for very little flow through that big sump... you'd probably want to add some circulation away from the display just to keep things moving... but other than that, I don't see a problem with it

rockstarta78 · Mar 2, 2018

I've always believed that you should try to maximize your water volume, thus, use the biggest sump you can get. I also use a refugium, and my thought process is your refugium should hold minimum 10% of your DT's water volume for it to be truly effective. I am a big on refugium (tho you wouldn't think that if you saw my refugium right now). I think natural way of exporting nutrient should always be high priority. Plus, a nice looking clean sump is really cool.

ca1ore · Mar 2, 2018

I have found, through some trial and lots of error, that sump volume simply for the sake of sump volume is mostly pointless. I always shoot for a sump that will hold all of the equipment I want it to hold, and will contain the most possible drain down water - usually ends up at about 1/3 of the display size. So, on my current 450 (400 net gallons of water), the sump is a 150. Any additional capabilities required (animal refugium, frag tank, RDSB) I do with separate tanks.

Potatohead · Mar 2, 2018

vlangel said:
I too always said as big as possible until I had the display tank overflow when the glue gave out on my hob overflow box and the back portion dropped down breaking the syphon.

I know most of you do not use hob overflow boxes and most of you have more than 1 standpipe so a mishap is minimized. (Actually that has been my only mishap in 10+ years and luckily I only had a 10 gallon sump at the time so only a couple gallons went on the living room floor). Still, anything is possible.

Now I have a 20 gallon sump for a 56 gallon tank. The sump probably holds 13 gallons of water with rock, sand and equipment displacement, but the return pump would probably run dry after 4 gallons, maybe less. That would be a mess but not not an all out disaster.

I have thought about using a 40B but never have because of the flood possibility. I guess if I built the return chamber small enough I could minimize the damage.

Or... you should baffle in a return chamber that only holds a few gallons or so.

Also comparing powerheads to return flow in terms of power consumption is not even close, as an extreme example say you can use two MP40's to get 50x turnover in the display, it is going to take WAYYYYYYY more power (and noise) to get that same turnover with a return pump.

Greybeard · Mar 2, 2018

rockstarta78 said:
I am a big on refugium <snip> a nice looking clean sump is really cool.

Agreed, on both points, but refugeums and 'nice looking clean sump' don't necessarily go hand in hand!

I know, the move these days is an empty refugeum, nothing but chaetomorpha. That's not the traditional use of a refugeum, though. Originally a refugeum was named such as a refuge... a place where critters could reproduce without the pressures they'd have in the main tank. Small shrimps, worms, various isopods and copepods, as well as various algaes. They'd have their own sand beds, live rock rubble, etc.

I'm moving away from that myself. My current ref started with a bunch of live rock rubble and loose de-nitrate media. The rock rubble is gone, the de-nitrate is in a filter bag... I still have to big chunks of live rock, covered in C. Mexicana... but I've got Chaeto on it's way, and will soon be pulling those rocks and all of the caulerpa out.

rockstarta78 · Mar 2, 2018

Greybeard said:
Agreed, on both points, but refugeums and 'nice looking clean sump' don't necessarily go hand in hand!

I know, the move these days is an empty refugeum, nothing but chaetomorpha. That's not the traditional use of a refugeum, though. Originally a refugeum was named such as a refuge... a place where critters could reproduce without the pressures they'd have in the main tank. Small shrimps, worms, various isopods and copepods, as well as various algaes. They'd have their own sand beds, live rock rubble, etc.

I'm moving away from that myself. My current ref started with a bunch of live rock rubble and loose de-nitrate media. The rock rubble is gone, the de-nitrate is in a filter bag... I still have to big chunks of live rock, covered in C. Mexicana... but I've got Chaeto on it's way, and will soon be pulling those rocks and all of the caulerpa out.

Agreed. I can't keep my refugium looking clean or nice. Vibrant killed my chaeto, which was expected. Now I need to get some chaeto again. For now, I only got rubble rocks, pods, worms, and couple of ............. get this........ peppermint shrimp. I wasn't planning on housing these shrimps in my refigium. But seeing how they were nipping on my new baby RBTA I had to remove them from the DT. There's still one hiding somewhere in the DT, which will be in my refugium when I get to catch it.

vlangel · Mar 2, 2018

Robin Haselden said:
Using a HOB overflow is asking for a flood. Might as well bring the water hose inside and just let it run.

I have used a hob overflow for over 10 years with only the 1 mishap. My current hob overflow box is not glued like my 1st one. I have a variable rate DC pump so the flow is exactly what the U tube and drain can handle. Bubbles never build up so the electricity can go off as often as it likes, the siphon always starts. They are reliable if they are set up right.