Return pump and skimmer math not adding up

[Mariette]

This is long winded but I’m really lost here and could use some help.

bought a new tank/stand/sump assuming it included a pump. I learned I was wrong. I assumed all pumps were created equally. Again, wrong. Assumed you buy the pump based on the volume of the tank. Wrong again. So, here’s what I’ve learned and it’s making NO SENSE

The return pump
you want a pump that will move 5 to 10 times the volume of the DT an hour. Is this true? If so, I’ve got a 110g tank so, 550-1,100 gallons per hour. Let’s average that out to 825 for simplicity’s sake.

Protein skimmer
I’ve been looking at a few and thought I’d go w the Red Sea RSK 300 Reefer Skimmer. At $400, it’s not cheap but it’s also not the most expensive one on the market. I went with it because it’s rated for an 80g SPS tank, 160g mixed reef, or 240g fish only tank. I’m planning on a 110g mixed reef so I figure this is good. No? But it says the “water flow” is 265g/hr.

Here’s where I’m lost: if the pump is moving 825g/hr through the sump but the skimmer is only treating 265g/hr, what’s the point? Just to get water moving through the filter sock? Aeration? Flow?!? Am I missing something?

Any insight would be appreciated. Thx

 

[ca1ore]

Comparing display turnover to skimmer processing is a false equivalency - there is no relationship one t’other. 5-10x is unnecessary in my experience. The main role of display turnover is to maintain even heating between sump and display, and to ensure proper surface skimming of the display. Both of these can be accomplished at 3-5X. I shoot for 3x. I also generally go for a skimmer that is rated for at least double my bio load.

 

[Mariette]

Comparing display turnover to skimmer processing is a false equivalency - there is no relationship one t’other. 5-10x is unnecessary in my experience. The main role of display turnover is to maintain even heating between sump and display, and to ensure proper surface skimming of the display. Both of these can be accomplished at 3-5X. I shoot for 3x. I also generally go for a skimmer that is rated for at least double my bio load.

I see. How does one calculate bio load? Am I overthinking this? Also, I know why you wouldn’t want a skimmer that’s not strong enough but can you go too strong? Assume not but I’m learning not to assume anything in this hobby

 

[Hermie]

If a return pump is theoretically turning over "infinity" amount of water per hour, then all of the water in the sump is the same water as in the display tank at any given instant.
The reverse of this is, if the return pump is turning over "zero" water per hour, then the display tank and the sump have completely "different" water in them at any given instant.

Since we want the skimmer to skim as much of the "whole system's water" as possible, higher turnover means more "balanced" skimming.

That said, some people run 3x turnover through sump, but some people run 10x or more. I run about 13x turnover on a nano tank (30 gal total). Triton requires 10x just to throw that out there.

 

[ca1ore]

That is a simple question with no good answer. The reason that skimmer ‘sizing’ is so imprecise is that there is no practical way to calculate bioload. I’ve been in the hobby for a longtime, and had dozens of tanks; so I usually eyeball it. Double/triple generally gets you into the right territory.

You generally don’t want such tepid flow from the display that the skimmer is removing less organics than it could; but beyond that there’s no appreciable improvement in going much above 5x that I’ve ever seen.

Clearly an undersized skimmer can be a problem; whether oversized is also a problem is less clear. I suppose if the skimmer holds more water than the display, it is too big lol. As example, my current system is a heavy bioload 700 gallons. My skimmer is a monster, rated conservatively for 3,000 gallons yet performs well. Just pick something that is rated for 2-3x your display and you’ll be within tolerance.

 

[Mariette]

That is a simple question with no good answer. The reason that skimmer ‘sizing’ is so imprecise is that there is no practical way to calculate bioload. I’ve been in the hobby for a longtime, and had dozens of tanks; so I generally eyeball it. Double generally gets you into the right territory.

You generally don’t want such tepid flow from the display that the skimmer is removing less organics than it could; but beyond that there’s no appreciable improvement in going much above 5x that I’ve ever seen.

Clearly an undersized skimmer can be a problem; whether oversized is also a problem is less clear. I suppose if the skimmer holds more water than the display, it is too big lol. As example, my current system is a heavy bioload 700 gallons. My skimmer is a monster, rated conservatively for 3,000 gallons yet performs well. Just puck something that is rated for 2-3x your display and you’ll be within tolerance.

Okay. You’ve been very helpful. Thank you. I’ve got some decisions to make then.

 

[Mariette]

If a return pump is theoretically turning over "infinity" amount of water per hour, then all of the water in the sump is the same water as in the display tank at any given instant.
The reverse of this is, if the return pump is turning over "zero" water per hour, then the display tank and the sump have completely "different" water in them at any given instant.

Since we want the skimmer to skim as much of the "whole system's water" as possible, higher turnover means more "balanced" skimming.

That said, some people run 3x turnover through sump, but some people run 10x or more. I run about 13x turnover on a nano tank (30 gal total). Triton requires 10x just to throw that out there.

Oh dear. It appears I’ve opened a Pandora’s box here. Back to the drawing boards then

 

[GTM42]

I would recommend looking at the BRS 52 weeks of reefing videos. They are very informative, and cover these topics well. I would separate out your skimmer and return pump, think of them as two different things. Your skimmer gph does not matter, only the size, and amount of skimate produced. I would also recommend the reef octopus or Nyos skimmers, as they are tried and true, the red sea is still new so I would be timid.

 

[Mariette]

@Cae

I would recommend looking at the BRS 52 weeks of reefing videos. They are very informative, and cover these topics well. I would separate out your skimmer and return pump, think of them as two different things. Your skimmer gph does not matter, only the size, and amount of skimate produced. I would also recommend the reef octopus or Nyos skimmers, as they are tried and true, the red sea is still new so I would be timid.

Ok. Will do. Thx!!!!

Edit: I just did a quick peruse of the titles and I must say.. mind. BLOWN. This is an amazing series of videos and I’m going to watch every single one. Can’t wait! Thank you

 

[GTM42]

Yeah I love it, I used that series when I was starting my first tank years ago. It came out at the exact same time that I setting it up. It was perfect.

 

[Mariette]

Yeah I love it, I used that series when I was starting my first tank years ago. It came out at the exact same time that I setting it up. It was perfect.

Great timing. I’ve got a lot to learn.

 

[homer1475]

Just be aware in those videos, that BRS is a company looking to sell products. While their videos are good and very informative, they also push a few products in those videos as well. While there is nothing wrong with that, going into them it's nice to know and keep in the back of your mind while watching.

 

[rob safron]

BRS had a recent video discussing exactly the flow through the sump. Video was not pushing any particular product. They propose that sump turnover does not need to be high as thought in the past. As low as 2x was fine. You need higher flow in the DT but that’s accomplished with power heads. I run about 3x through the sump myself.

 

[Mariette]

What? No black and white cookie cutter answer? More options to customize? Excellent

 

[rob safron]

Yep. 2-5 was acceptable per video.

 

[WVNed]

The cookie cutter answer is a Sicce Syncra Silent 4.0 pump or something similar for your size tank.
https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/syncra.pdf
What kind of drain does your tank have and how much water can you push quietly? Always something to think about.
A long time ago I read the same stuff you are now and decided on 6x tank volume through the sump. It has worked for 10 years. Some do way more and some less. More costs money because of bigger pumps and plumbing. Less is not suitable to me because of my skimmer size.
I am running a Sicce Syncra Silent 3.0 on my 75 and have 2 Sicce Syncra Silent 4.0s waiting here for the 280 tank I have ordered. Before buying them I had to make the same decisions you are making now. It's just twice as big so I got 2.

Pump rated flow is nice to shop with. You need to look for a head height chart for a pump you are interested in. Head height is the distance the pump has to lift the water. Pumps are sold by how much they would flow with nothing attached. You get a lot less when you pump it into piping and start pumping uphill.

 

[ca1ore]

What? No black and white cookie cutter answer? More options to customize? Excellent

Part of the reason that you see recommendations that are all over the place is that none of it needs to be that precise. So, yes, you probably are overthinking it. I’m just glad that when I was cutting my reefing teeth that there was no internet. I just had a fellow reefer that really knew what he was doing and I just followed his advice. Otherwise you’ll get tons of advice, with no way to really know whether the person actually know of what they speak. One of the early reefing pioneers, David Saxby, always used to say before take somebody’s advice ask to see their tank.

If I were you, just get a pump that gives you about 5x flow and a skimmer that is rated for 2-3x display size. If you stick with the hobby, upgrading is part of the fun of it.

 

[Mariette]

The cookie cutter answer is a Sicce Syncra Silent 4.0 pump or something similar for your size tank.
https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/syncra.pdf
What kind of drain does your tank have and how much water can you push quietly? Always something to think about.
A long time ago I read the same stuff you are now and decided on 6x tank volume through the sump. It has worked for 10 years. Some do way more and some less. More costs money because of bigger pumps and plumbing. Less is not suitable to me because of my skimmer size.
I am running a Sicce Syncra Silent 3.0 on my 75 and have 2 Sicce Syncra Silent 4.0s waiting here for the 280 tank I have ordered. Before buying them I had to make the same decisions you are making now. It's just twice as big so I got 2.

Pump rated flow is nice to shop with. You need to look for a head height chart for a pump you are interested in. Head height is the distance the pump has to lift the water. Pumps are sold by how much they would flow with nothing attached. You get a lot less when you pump it into piping and start pumping uphill.

The cookie cutter answer is a Sicce Syncra Silent 4.0 pump or something similar for your size tank.
https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/syncra.pdf
What kind of drain does your tank have and how much water can you push quietly? Always something to think about.
A long time ago I read the same stuff you are now and decided on 6x tank volume through the sump. It has worked for 10 years. Some do way more and some less. More costs money because of bigger pumps and plumbing. Less is not suitable to me because of my skimmer size.
I am running a Sicce Syncra Silent 3.0 on my 75 and have 2 Sicce Syncra Silent 4.0s waiting here for the 280 tank I have ordered. Before buying them I had to make the same decisions you are making now. It's just twice as big so I got 2.

Pump rated flow is nice to shop with. You need to look for a head height chart for a pump you are interested in. Head height is the distance the pump has to lift the water. Pumps are sold by how much they would flow with nothing attached. You get a lot less when you pump it into piping and start pumping uphill.

Didn’t know head height was a thing but it makes sense. Ugh. Why do I get the feeling I’m in over my head? If I had to choose a number, based on all my research so far, I’d go w 5 times DT volume per hour. Will have to consider head height too. Why do I get the feeling I have to buy hoses for this thing? Not home improvement store ones that may have chemicals but overpriced fish store ones? Say it ain’t so

 

[Mariette]

The cookie cutter answer is a Sicce Syncra Silent 4.0 pump or something similar for your size tank.
https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/syncra.pdf
What kind of drain does your tank have and how much water can you push quietly? Always something to think about.
A long time ago I read the same stuff you are now and decided on 6x tank volume through the sump. It has worked for 10 years. Some do way more and some less. More costs money because of bigger pumps and plumbing. Less is not suitable to me because of my skimmer size.
I am running a Sicce Syncra Silent 3.0 on my 75 and have 2 Sicce Syncra Silent 4.0s waiting here for the 280 tank I have ordered. Before buying them I had to make the same decisions you are making now. It's just twice as big so I got 2.

Pump rated flow is nice to shop with. You need to look for a head height chart for a pump you are interested in. Head height is the distance the pump has to lift the water. Pumps are sold by how much they would flow with nothing attached. You get a lot less when you pump it into piping and start pumping uphill.

The cookie cutter answer is a Sicce Syncra Silent 4.0 pump or something similar for your size tank.
https://media.cdn.bulkreefsupply.com/media/wysiwyg/PDFs/syncra.pdf
What kind of drain does your tank have and how much water can you push quietly? Always something to think about.
A long time ago I read the same stuff you are now and decided on 6x tank volume through the sump. It has worked for 10 years. Some do way more and some less. More costs money because of bigger pumps and plumbing. Less is not suitable to me because of my skimmer size.
I am running a Sicce Syncra Silent 3.0 on my 75 and have 2 Sicce Syncra Silent 4.0s waiting here for the 280 tank I have ordered. Before buying them I had to make the same decisions you are making now. It's just twice as big so I got 2.

Pump rated flow is nice to shop with. You need to look for a head height chart for a pump you are interested in. Head height is the distance the pump has to lift the water. Pumps are sold by how much they would flow with nothing attached. You get a lot less when you pump it into piping and start pumping uphill.

Didn’t know head height was a thing but it makes sense. Ugh. Why do I get the feeling I’m in over my head? If I had to choose a number, based on all my research so far, I’d go w 5 times DT volume per hour. Will have to consider head height too. Why do I get the feeling I have to buy hoses for this thing? Not home improvement store ones that may have chemicals but overpriced fish store ones? Say it ain’t so

 

[Mariette]

Part of the reason that you see recommendations that are all over the place is that none of it needs to be that precise. So, yes, you probably are overthinking it. I’m just glad that when I was cutting my reefing teeth that there was no internet. I just had a fellow reefer that really knew what he was doing and I just followed his advice. Otherwise you’ll get tons of advice, with no way to really know whether the person actually know of what they speak. One of the early reefing pioneers, David Saxby, always used to say before take somebody’s advice ask to see their tank.

If I were you, just get a pump that gives you about 5x flow and a skimmer that is rated for 2-3x display size. If you stick with the hobby, upgrading is part of the fun of it.

Interesting...May I see a picture I’d your tank?

I’m kinda leaning towards 5xs and I’d heard the advise re skimmer and was going w double the display size. Think 3xs would be cool but I’ve noticed these things don’t come cheap lol