Tank turnover sump based set up ?

Edgee50 · 2025-08-01T18:04:03-0400

Hi guys

I have been keeping cichlids for more than 10years , I was recently about to give it up , but just upgraded everything a few months back !

Originaly had a 450ltr and 240ltr tank side by side , decided to just get a bigger tank , went for a

Red Sea reefer s1000 g2 ,using it for freshwater and a lot American / Malawi cichlids …

This is my first “sump” tank

It’s 1000ltrs total

Display is 800ltrs

Sump is 200litrs ..

Anyway all is good with my set up etc

Water perimeters are all good !

I was hoping to get some advise on

“Tank turnover per hour “

Iam currently at 3500lph

Approx 5x times per hour of display tank , I have a lot of large heavy rocks in display tank side, so Iam guessing I have about 700ltres in display tank ,

I have installed a

Reefmat 1200 , and have modified it to run on freshwater with floats !

This works very well , and if anyone want wiring specs to this , I will share !

I have a lot of stock in tank (50 maybe more ) Large small / Reefmat is using a lot of fleece , and I know cichlids are a messy fish !

So what is your recommended turnover per hour , I was hoping to maybe reduce mine !

I have plenty of media in sump

I have 4 x wave makers

Plenty of air also in display tank!

I’ll share some pics

HUKIT · 2025-08-01T20:06:17-0400

I don’t have a single sump that turns the tank volume more than 4 times per hour. You can use your wavemakers if you’re looking for in tank flow. I prefer a slower turn over.

Midwater · 2025-08-01T20:49:40-0400

My large tank is about three thousand litres and the sump is about eight hundred litres. My pump is also pushing about three thousand five hundred litres/hour. That is only about one in ten, and it seems to work well.

If you have a reasonably sized sump, I think a slower turnover is perfectly good.

tlindsey · 2025-08-01T21:06:04-0400

Edgee50 said:
Hi guys

I have been keeping cichlids for more than 10years , I was recently about to give it up , but just upgraded everything a few months back !

Originaly had a 450ltr and 240ltr tank side by side , decided to just get a bigger tank , went for a

Red Sea reefer s1000 g2 ,using it for freshwater and a lot American / Malawi cichlids …

This is my first “sump” tank

It’s 1000ltrs total

Display is 800ltrs

Sump is 200litrs ..

Anyway all is good with my set up etc

Water perimeters are all good !

I was hoping to get some advise on

“Tank turnover per hour “

Iam currently at 3500lph

Approx 5x times per hour of display tank , I have a lot of large heavy rocks in display tank side, so Iam guessing I have about 700ltres in display tank ,

I have installed a

Reefmat 1200 , and have modified it to run on freshwater with floats !

This works very well , and if anyone want wiring specs to this , I will share !

I have a lot of stock in tank (50 maybe more ) Large small / Reefmat is using a lot of fleece , and I know cichlids are a messy fish !

So what is your recommended turnover per hour , I was hoping to maybe reduce mine !

I have plenty of media in sump

I have 4 x wave makers

Plenty of air also in display tank! View attachment 1564861 View attachment 1564862

I’ll share some pics

Welcome aboard

danotaylor · 2025-08-01T23:12:48-0400

In terms of biological filtration contact time with the media is the most relevant. Super high flows through the media bed do not allow for the bacteria to adequately convert the biological waste to less harmful nitrate. It's be like trying to grab your food from the drive through window at 40mph. The term "over filtered" is only true in the mechanical sense, not the biological sense. The bacterial colony can never exceed it's food source. Providing you have adequate media for your bio-load & the bacterial colony it makes zero difference if you have 5 times the amount of media your bio-load can feed.
As already mentioned, your wave makers will provide "flow" for your fishes & mobilize solid waste to your overflows where it will be filtered out by the filter socks. Your turn over rate proves to be good if your ammonia & nitrite levels are 0 & you are producing nitrate.
Vacuum waste from the tank floor, and keep up a regular water change schedule! Happy fish keeping :thumbsup:

Edgee50 · 2025-08-02T04:17:52-0400

Thnks for this guys !
I would have thought alrite that the water going through sump would need to ”dwell” a while there alrite rather than speed through as yous have mentioned , I’ll drop to 3x turnover and monitor
Thank you for help

duanes · 2025-08-02T08:25:16-0400

My tank is 180 gal (580 liters using) , using a 125 gal (450 liters) as a sump, and uses a 1500 gph (5600 lph( pump) to recirculate(and a couple wave makers).
But i keep rephillic cichlids,
to me rate, and flow is not determined by some arbitrary, or generic number, but more but the DO needs of the cichlid species kept.
If for example Angelfish or severums are kept that require slow flow, and less DO, a low turnover may be fine.
If higher DO needing species such as Geophagus or Tomocichla are kept, they may require a much stronger rate to promote the higher DO needed.
Wave makers may serve to accomplish this, but also placement of efluent ports to help activate turbulence in the tank, (and sump) to promote aerobic activity). This is my normal sump tp tank turbulence for my rheophiles.

Because this is the riverine flow where I catch them.

and because media needed is determined not by volume, but by waste output by the fish (food to microorganism ratio),
amount of media is mostly not irrelevant.
A couple 3" gags of bio-media is often sufficient for most tanks.
More importantly it is theareobic needs of the bacteria (and fish species) that determine flow rate over, and thru that media.
Once a tank is cycled, water changes and plant species using nitrate as food are more relevant.
Like the low nitrate levels my fish experience in nature