How much turn over does your sumo do?

[drolmaeye]

I know it might sound funny but your overflow and sump are ultimately going to determine your GPH not your return pump.

They might set the limits, but there is a lot of play within those limits, no? I feel like in my case I adjusted my return pump to get the flow (turnover) I wanted, and then adjusted the gate valve on my main drain so I had steady water level in my overflow.

 

[RocketEngineer]

2-3 is what I have used for years.
Imo, your skimmer is more efficeint with lower flow as you get more contact time.

You realize that a skimmer is a multi-pass filter so in reality it has 24/7/365 contact time, right? If it doesn’t collect some specific particle the first time through, it’s got a chance the next time it comes back around.

 

[RocketEngineer]

@OP I take the approach that as long as the water in the sump has the same basic water parameters as the display, then there is enough flow throughout the system. Sure, the equipment in the sump will push those parameters towards the desired range (that’s the point of having said equipment), but for the most part it should be hard to differentiate the parameters of the two water volumes. On a big system, 0.5X might still be hundreds of gallons moving per hour. The exact number is meaningless. It’s the goal of consistent parameters that matters.

 

[mues]

Does the higher turn over keep your tank cleaner or is it subjective to what you put in your sump

I don't know that it's any cleaner than it would be with lower turnover. I have high baffles and a large sump. Most of the debris is caught unless my ATO runs out of water.

 

[exnisstech]

I have to be honest with 4 tanks running I have no idea what the turn over rate is on any of them.

 

[BigAl07]

My return /sump is roughly 4x-5x but my In-Tank is much higher via other means of water movement. Years ago I initially relied on the return/sump to create the majority of my In-Tank flow and it just seemed like too much through the sump. I changed over to the method of using in-tank powerheads etc for that flow instead of passing crazy amounts of water through the sump and the tank became a new (and much better) habitat.

It's the best of both worlds (except on the wallet lol).

 

[AnomMatty]

Been researching this lately myself as I'm in the process of setting up my first reef, so thought I'd throw in my 2c. This is all my opinion based on what I've learned.

A couple (not all) determining factors for how much turn over you want:
-Type of livestock you plan to keep - Softies/LPS require less flow, SPS higher - sump turnover is one way to provide flow through the display - I'm sure theres arguments for more flow through filter socks in a FOWLR vs less

-Type of filtration you plan to utilize in the sump and how you wish to utilize it - most refugium info is focused around fairly low flow, some prefer low flow for protein skimmers, etc.

I took the approach of having a fairly wide rate of flow available, and the ability to adjust that flow through the return and overflow sides. Running a 600gph overflow and adjustable return pump rated for 660gph - I can theoretically run up around 15x flow (which is probably overkill), but can run much lower flow rates by adjusting the gate valve and return pump down, which I feel is ideal.

All that to say that, ultimately, flow rate through the sump is one of the less important parameters in terms of display turnover, and more about finding a rate that is utilizing the equipment in the sump effectively and working for your setup.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, I think the whole concept of turnover was mostly used when the tank flow was driven by sump flow.

Now that most people use other means, such as in tank pumps, its meaning is largely unimportant as long as it is not too low.

Once per hour seems more than enough to be sure the display tank water gets treated with whatever means you are using.

Of course there can be exceptions, such as dosing hydroxide for alk where you want to dilute it quickly, but that's a case by case consideration.

 

[X-37B]

You realize that a skimmer is a multi-pass filter so in reality it has 24/7/365 contact time, right? If it doesn’t collect some specific particle the first time through, it’s got a chance the next time it comes back around.

Yea I get it but im not a rocket engeneer. I did do 7 years with Morton Thiokal as a chemical engeneer, lol.
Its all good, I just prefer a slower contact time through my sump. Over the last 30+ its worked well for me.

 

[KStatefan]

I am at about 4.5 times total volume

 

[BigAl07]

I just did some tweaking and then ran the the math on my system. I currently have 2x of my total tank volume going through the sump. With the in-tank flow devices I think that's more than enough and it gives sufficient "dwell time" and should be "easy on" the Pod-pulation once they get established.