Do you have enough flow?

[inktomi]

I thought this paper was pretty incredible. Going with the flow: How corals in high‐flow environments can beat the heat. We all know that SPS coral need a lot of flow - but have you ever thought of why? It's sort of just taken as a given that you need 50x, 70x, 100x or more water turnover in our SPS tanks - but no one ever really explains why.

It turns out, from the paper, corals growing in high flow locations have a genetic response to the water movement. They seem to grow faster, they spend more energy on life, photosynthesis increases, they capture more food, and they make better use of that food that they do capture. It's pretty incredible!

The paper is comparing two locations on a reef in Guam, a high flow (8-16 cm/s) and a low flow (4 cm/s) part of a single reef. They're looking at RNA and the genes that get expressed differently between the two locations because over recent bleaching events more than 80% of coral died in the low flow area, where less than 20% of coral died in the high flow area. It's a really incredible paper - I encourage you to check it out.

Also, to convert between cm/2 and something like gallons per hour I think that we can just sort of jump to cubic centimeters/second and then use equations for water flow through a pipe - maybe? Should at least get in the ballpark, right? Doing that my tank is just a little over the low flow part of the reef - I never would have guessed as it's set up for my Achilles tang and I've always thought of it as a high flow tank.

 

[MnFish1]

I thought this paper was pretty incredible. Going with the flow: How corals in high‐flow environments can beat the heat. We all know that SPS coral need a lot of flow - but have you ever thought of why? It's sort of just taken as a given that you need 50x, 70x, 100x or more water turnover in our SPS tanks - but no one ever really explains why.

It turns out, from the paper, corals growing in high flow locations have a genetic response to the water movement. They seem to grow faster, they spend more energy on life, photosynthesis increases, they capture more food, and they make better use of that food that they do capture. It's pretty incredible!

The paper is comparing two locations on a reef in Guam, a high flow (8-16 cm/s) and a low flow (4 cm/s) part of a single reef. They're looking at RNA and the genes that get expressed differently between the two locations because over recent bleaching events more than 80% of coral died in the low flow area, where less than 20% of coral died in the high flow area. It's a really incredible paper - I encourage you to check it out.

Also, to convert between cm/2 and something like gallons per hour I think that we can just sort of jump to cubic centimeters/second and then use equations for water flow through a pipe - maybe? Should at least get in the ballpark, right? Doing that my tank is just a little over the low flow part of the reef - I never would have guessed as it's set up for my Achilles tang and I've always thought of it as a high flow tank.

Forgetting the paper for a second, the flow of the tide in the average protected reef is 100x what we have in our tanks. If you have flow directed in one direction 24/7 - to me that is probably a mistake.

 

[inktomi]

I agree - the flow has to be diffuse, it can't just be blasting things. That's what hard - getting so much flow yet keeping it from power washing the tissue off things.

 

[Billdogg]

I use a pair of Gyre 250's on their programmer, and several Koralias on theirs so that there is rarely a calm moment and often a tremendous amount of varied flow. Because they are controlled separately, what is on and when is constantly changing. I feel that the tank and it's corals benefit greatly from it.

 

[inktomi]

I use a pair of Gyre 250's on their programmer, and several Koralias on theirs so that there is rarely a calm moment and often a tremendous amount of varied flow. Because they are controlled separately, what is on and when is constantly changing. I feel that the tank and it's corals benefit greatly from it.

Would you recommend the Gyres? I was thinking about maybe adding two in the back of my tank, one each side of my overflow. Good diffuse flow? I've never used them - I've been a long term Vortech user.

 

[Garf]

Would you recommend the Gyres? I was thinking about maybe adding two in the back of my tank, one each side of my overflow. Good diffuse flow? I've never used them - I've been a long term Vortech user.

I got 2 maxpect 230s (either side of overflow) and 2 Koralias on a 60g cube, and a good sump return flow. I love ‘em. Lots of flow, and when the corals grow I can turn the gyres up (only 50% ocean gyre setting now).

 

[Billdogg]

Would you recommend the Gyres? I was thinking about maybe adding two in the back of my tank, one each side of my overflow. Good diffuse flow? I've never used them - I've been a long term Vortech user.

I really like them. More, and very diffuse, flow than anything I’ve ever used. Placement can be tricky. I have them on the back of my standard 120 on either side of a center overflow. Too high up - or angled up too much - and there is a standing wave running over the front. They’d be great on opposite ends but I don’t care for the obstructed view.
My corals seem to love them.

 

[inktomi]

Ah, yea a wave at the front is something I didn't consider! I saw the newest versions (not sure how new they really are..) have a new guide on them so you can put them all the way at the surface of water - but if they push 5,000 GPH straight out a wave at the front is exactly what that would produce. Good info!

 

[lefkonj]

Interesting timing. I just turned down my vortech from 65% to 35% capacity. Things look much happier.

 

[IamChrismWard]

What reefs in Guam? I have close to a 1000 hours diving in Guam there is a huge chance that I dove the reefs they studied.

 

[inktomi]

They were studying two places near West Hagatna Bay.

13 28'55.2" N, 144 44'42.72" E according to the paper.

 

[jmichaelh7]

I have gyre 350 on both ends of my tank. Different settings and the sps seem to like it.

 

[kerbfish]

I’d say in theory high flow is great and is prob proven to be better for SPS. My softies can’t even handle my maxspect gyres at 20%....so I just won’t turn them up....even though I’d like to...my tank is a 130 display....so not tiny...

 

[inktomi]

Yea, that's the downside to compressing a whole reef into our tanks. In the wild there is much more separation between SPS and LPS.

That said, take the paper as a source of information. The coral in our tank doesn't suffer from the same environmental stressors that the wild coral does, so some of these genes are unlikely to be as useful in what we like to think is perfect conditions for our coral.

 

[arie_corals]

I have two ice cap 4K on each side and on right towards the bottom is a mp40. I’m running the mp40 on constant 35% day time and night I run 20%. The left ice cap is on random one direction 25%-75% and the right icecap is random with invert rotation and reverse allowed at 25%-65%. Ice cap at night is constant 30%. Oh and for return pump I’m pushing around 430 gph. Coral seem happy... the idea of the mp40 is to keep a constant flow behind the rocks on the back side of the tank. Seems to work. Tank is 80 gallon Display.

 

[chris new reefer]

I really like them. More, and very diffuse, flow than anything I’ve ever used. Placement can be tricky. I have them on the back of my standard 120 on either side of a center overflow. Too high up - or angled up too much - and there is a standing wave running over the front. They’d be great on opposite ends but I don’t care for the obstructed view.
My corals seem to love them.

Hi @Billdogg

Do you have them horizontally or vertical?
I have the same tank size with center overflow and I have mine horizontally.
They are both running in random mode and I really like the flow.
All my corals ( all LPS) are doing great.

The only thing that I have is the feeling that a lot of small particles are not reaching the overflow.
The water is crystal clear but with a lot of particles.
And when I watch the overflow closely, I can see a lot of particles just flowing by and staying in the gyre flow.
Return flow rate is around 4 times tank volume.

So what is your set up with those pumps?
Thank you so much for your help!

 

[Cdime712]

Forgetting the paper for a second, the flow of the tide in the average protected reef is 100x what we have in our tanks. If you have flow directed in one direction 24/7 - to me that is probably a mistake.

How so ?

 

[MnFish1]

How so ?

I probably wasn't clear - I meant if you have flow constantly blowing on coral hard on one direction - it seems to cause problems (or can cause problems). As colonies grow for example - if there is only flow in one direction constant - it can result in too high flow near the pump and less and less downstream as coral grows. Having flow that is only in one directly can lead to 'dead zones' more quickly than an alternating or more turbulent flow. IMO

 

[Cdime712]

I probably wasn't clear - I meant if you have flow constantly blowing on coral hard on one direction - it seems to cause problems (or can cause problems). As colonies grow for example - if there is only flow in one direction constant - it can result in too high flow near the pump and less and less downstream as coral grows. Having flow that is only in one directly can lead to 'dead zones' more quickly than an alternating or more turbulent flow. IMO

Got it. I'm new to this I'm always looking on ways to improve my tank. The flow is always something I get mix answer on. I have my tank with flow and all directions.

 

[jassermd]

I’d say in theory high flow is great and is prob proven to be better for SPS. My softies can’t even handle my maxspect gyres at 20%....so I just won’t turn them up....even though I’d like to...my tank is a 130 display....so not tiny...

I’m completely with you on that! I have. 280g DT and have only 2 Neptune WAVs, one on either side set on “Malibu” at 8% and my LPS love it. If I turn them up any,more than that, all the torches and hammers clamp up.
Oh well... it’s their ecosystem not mine!