Flow, flow and more flow.

[les]

It has often been said flow is one of if not the most important thing we add to our reef aquariums esp SPS dominated. The more corals you have so the flow is diminished and even more so as those SPS grow and fill out all areas of the tank. How much flow should I have and do I have too much flow in my aquarium are regular questions that pop up on reef forums. The simple answer is enough flow to benefit whatever corals you have and not so much as to inhibit their expansion and growth. Now that is easier said than done I know.

Take my own tank 100 gallons with sump. My DT measures 54" long X 20" deep X 19" front to back. I started with 2 Maxspect Gyre FX-150s at opposite ends of the tank, as my corals grew I could see the flow reducing slightly so I added a FX130 vertically in the rear corner to provide a different kind of flow around the rear of my reefscape.

I have now added a Tunze 6040 pump half way down the front right hand end of the tank with another ordered to go in the left hand front corner. 5 pumps plus my Jebao DC8000 return pump. My tank is a mixed reef with mainly SPS but also LPS and the odd softie. Corals are all doing great esp my SPS which love the flow but I can't see me adding anymore flow ..........well at least not for some time to come.

 

[372xp]

Very true Les, if your sand bed isn't shifting you don't have enough flow. I have 2 MP40's in a 4 foot tank and still think I could use a couple of MP10's on the back wall. If you think about the last time you went paddling at the beach and remember the pull around your ankles, that is kind of what to aim for. Even the latest in wave pumps can't replicate this sort of movement in a rectangular box.
The importance of strong flow on growth of SPS can some way be explained by this diagram.

Seeing as the corals can't directly absorb the calcium carbonate through there skin the strong flow helps the passage of carbonic anhydrase through the tissue=strong healthy growth.

 

[372xp]

I will demonstrate the effects of flow on coral growth using examples of some acropora in my tank.
This acro is demonstrating growth towards the flow. It is quite obvious here how the growth is much stronger on the side which gets the most flow.

This is the same coral as the one above a.valeda. Here you can see how growth is affected by too much flow. The squat almost encrusting form is not the form this acro normally would take.

This coral is in an ideal position getting strong turbulent flow from all directions. This will produce a much more typical pleasing growth form.
All these acropora were grown from frags over the last year, and you can see the importance of correct placing in the flow.

 

[les]

I will demonstrate the effects of flow on coral growth using examples of some acropora in my tank. View attachment 136501
This acro is demonstrating growth towards the flow. It is quite obvious here how the growth is much stronger on the side which gets the most flow.
View attachment 136502
This is the same coral as the one above a.valeda. Here you can see how growth is affected by too much flow. The squat almost encrusting form is not the form this acro normally would take.
View attachment 136503
This coral is in an ideal position getting strong turbulent flow from all directions. This will produce a much more typical pleasing growth form.
All these acropora were grown from frags over the last year, and you can see the importance of correct placing in the flow.

Yep agree 100% along with the correct temperature as man apparently keep their temperature too low causing undue stress to their corals. Interesting article here.
https://reefs.com/magazine/the-great-temperature-debate-i-59/

 

[cuprajake]

i have lps dominant, so flow becomes important.

sps tanks you can just blast them. lps you can rip the flesh

 

[372xp]

i have lps dominant, so flow becomes important.

sps tanks you can just blast them. lps you can rip the flesh

LPS need lots of flow/movement to. Just a different,in most cases,type of flow. What you need to consider, when adding corals to your tank, is the location of the corals in their natural environment.
What [MENTION=17165]les[/MENTION] is doing using 3 gyres and a Tunze is trying to replicate a shallow reef environment. If your corals come from elsewhere you will need to use careful placement or a different type of flow.
Basically corals found at a depth of up to 12 meters require turbulent high energy flow.
Corals at a depth of below 12 meters prefer a more laminar flow. This being water that moves continually in one direction like an ocean current. This can speed up or slow down but needs to be consistent.
Lagoonal corals like a tidal flow. Strong left 8 hours strong right 8 hours turbulent to slack 8 hours. Ramped up and down either way.
But since most of us like to mix it up a bit it is placement in the environment that is important. Because the most efficient (in terms of nutrient removal) is turbulent flow. Notice Les has some large soft corals in the middle of his tank. These look healthy so he proves you can be successful with strong flow.
When my lights come on I will show pictures of my LPS placement in strong flow showing what works and what doesn't.

 

[cuprajake]

i know like, but if i have too much flow my lps wont expand enough

 

[Bob1888]

Nice post Les and it just reminded me to clean my heads which is a good tip especially with the likes of gyres it's amazing the drop off in flow if you don't keep a regular cleaning regime

 

[les]

Cheers guys. This video will give you some idea of the flow created in my tank. I have another Tunze 6040 to get hopefully next week which will compliment the one I have on the far RH side but positioned on the far left.

https://www.youtube.com/watch?v=_j4557myQCg

372xp you are so right with your post, appreciate it.

 

[372xp]

[MENTION=22549]cuprajake[/MENTION] look at Les' video and see how much flow his Duncan's are getting. This sort of turbulent flow is maximising it's chance of a decent feed. It is fully extended unlike mine which tends to get a more laminar flow. It only really comes out fully 2 or 3 times a day as the MP40's go through there cycles.
On the other hand my torch and one of my hammers really love there position under one of the Wavemaker where they get that all important upwelling current.

 

[cuprajake]

personally think that's too much flow for duncans.


these are mine

- - - Updated - - -

btw ignore the cyano, moved to triton n got hell of an outbreak

 

[cuprajake]

oh and the tank

 

[372xp]

There's nothing wrong with that. Looks beautiful. I think it's easier to manage your flow in a smaller tank, good job.

 

[les]

personally think that's too much flow for duncans.


these are mine

- - - Updated - - -

btw ignore the cyano, moved to triton n got hell of an outbreak

They don't seem to mind it at all, are growing and reproducing well

.

 

[cuprajake]

i think with lps they can be adjusted to higher flow, if its a slow increase

 

[les]

i think with lps they can be adjusted to higher flow, if its a slow increase

Quite possibly the case.