Do we overlook flow?

ScottR

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I came home the other night and my tank was almost lights out. Corals didn’t look happy. I told myself I’d sleep on it as it was almost lights out. Woke up the next day and after the lights came on, things still didn’t look great. Duncan shriveled up, sarmentosa had it polyps retracted which is rare. RBTA was even closed up which is never. My immediate thought was to test parameters. But I noticed the water agitation on the top wasn’t great. So I checked my return pump. Chaeto had snuck through and clogged the pump and so some detritus had built up. I cleaned the pump and hooked it back up and things were normal after a couple of hours.

I sometimes see posts here about corals not doing well and being closed up and I wonder if flow is an issue. Lighting is easy To master, especially with a PAR meter. I tend to do heavier flow with powerheads. I think some are scared off of too heavy of flow. Do we overlook flow?
 
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ScottR

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Just to play devils advocate here: I think that your corals were responding to the sudden chance in their environment. You righted the ship, returned things to normal, and your responded in kind.

but yes: flow is EXTREMELY important!
Very well could be. Could have been filtration was blocked and nitrates jumped, lack of oxygen, rise in CO2 and therefore drop in pH, etc. I always keep an open mind.
 

pcon

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I agree flow is super important, I once went on a trip and the tank sitter didn't notice that the in tank flow pumps were off for a whole week. Lost a Pipe organ coral to that, and some other corals were unhappy but some SPS and other corals seemed happier after the week with only the return flow. So perhaps flow can be a double edged sword. I think the right flow is very important, too much can be as detrimental as too little, but this is true of so many things in the hobby.

There is something interesting to be said in the hobby we don't generally have tools to measure flow. Characterizing, turbulent, pulsing, laminar is something that isn't often talked about and even more uncommon to see measured in tank or in the wild. With chemistry, and lighting where we have had lots of hard data from PAR meters, ICP testing, home test kits, and the like, there is a lot of discussion of Ideal water parameters and lighting. For flow we only sometimes roughly measure return pump output, there are no common tools in the hobby for measuring flow in tank at the corals. There are a few tools which are used by academics and research institutions, for in situ measurements, but I almost never see these referenced in the hobby and have never seen one used in a home tank. And these tools often leave out important factors in our tanks, which is a more subjective characterization of the flow over time, and the direction or shape of the flow, Is the flow turbulent, pulsing, constant, and how does it move around the coral is it coming from multiple directions, up, down, swirling, ect. Objectively measuring and describing the important aspects of flow is something that seems to be totally missing from the hobby.
 

Gareth elliott

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@ScottR
I think this means that you need to test for us.
Sure you can find a Acoustic Doppler velocimeter. If unsure just say that out loud when on a bus or other crowded area. Think Marlon Brando and “Stella”.

When someone reacts follow them home, sneak in(i recommend using a bush to hide in). And borrow the equipment.
Now you can test periodic flow of an open to air system.
But before you go watch “To catch a thief” for inspiration. Could the chaeto have been releasing alleopathic chemicals as it was being hit with the propeller snagged in the pump?
 
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@ScottR
I think this means that you need to test for us.
Sure you can find a Acoustic Doppler velocimeter. If unsure just say that out loud when on a bus or other crowded area. Think Marlon Brando and “Stella”.

When someone reacts follow them home, sneak in(i recommend using a bush to hide in). And borrow the equipment.
Now you can test periodic flow of an open to air system.
But before you go watch “To catch a thief” for inspiration. Could the chaeto have been releasing alleopathic chemicals as it was being hit with the propeller snagged in the pump?
As for the acoustic thingy, no idea. Marlon Brando, not my time. To catch a thief, he got away. As for the chaeto, possible. But the flow really was blocked. I mean there was no suction and water movement. I don’t mean to hate on HOB tanks, but I wonder if they can get enough flow in their tanks with just a trickle and a powerhead. I often see these tanks in the help threads.
 

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flow is more important than light, I read more and more that you can’t have too much flow but recently the tissue was ripped off my guttatus from too much indirect random flow!
i think getting flow right is one of the hardest things to accomplish in a tank.
you don’t really want high flow, you want high water moving volume, the Best place for my pumps always seams to be a meter away from the tank lol.
 

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I was trying to run the 13.5 g with just an upgraded return, I added a little 1200 lph powerhead a week or so ago and all the corals except xenia love it!
 
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flow is more important than light, I read more and more that you can’t have too much flow but recently the tissue was ripped off my guttatus from too much indirect random flow!
i think getting flow right is one of the hardest things to accomplish in a tank.
you don’t really want high flow, you want high water moving volume, the Best place for my pumps always seams to be a meter away from the tank lol.
I see so many threads with people saying euphyllia aren’t doing well. And many people say to put in low flow. And to which I think, why not increase flow? I don’t want to give improper advice but just my thinking.
 

Gareth elliott

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As for the acoustic thingy, no idea. Marlon Brando, not my time. To catch a thief, he got away. As for the chaeto, possible. But the flow really was blocked. I mean there was no suction and water movement. I don’t mean to hate on HOB tanks, but I wonder if they can get enough flow in their tanks with just a trickle and a powerhead. I often see these tanks in the help threads.

Had to watch years ago for a literature class. Now you know the proper way ti get someone’s attention.

Do wish there were ways to test flow that were not lab equipment.

Have contemplated throwing rock for new builds on a 3d scanner and placing the scans in a digital wind tunnel to optimize placement lol.

I think I run conservatively around 40-50x my display volume. For me, using more flow decreases the chances of algae on my gorgs and the goni and acros grow faster For me.
I also Have not noticed a negative effect on my euphylia.
 

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I agree that flow is something we rarely talk about and it is extremely important. There are very few tanks with proper flow and if you SCUBA dive, especially around shallow reefs you will see that no matter how large our pumps, we won't be able to duplicate flow on a reef.

Even where waves are crashing corals are growing. I am not sure how they do it and it would give me a headache.

In my own tank I just installed one of those powerheads that is a foot long and spans almost the entire side of my tank. I can't turn it up full speed or it would splash all the water out of my tank.

My arrow crabs are holding on for dear life with one claw and shooting me dirty looks.
But with his other claw, he still manages to grab some lunch.

My Fireclowns are still spawning even though the current won't allow them to stay near their nest. But they manage to get up spurts of sped to do it.

My corals are all really loving it but the bristle worms keep getting knotted up with each other. :rolleyes:

High current is the way to go for "most" creatures.
 
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Had to watch years ago for a literature class. Now you know the proper way ti get someone’s attention.

Do wish there were ways to test flow that were not lab equipment.

Have contemplated throwing rock for new builds on a 3d scanner and placing the scans in a digital wind tunnel to optimize placement lol.

I think I run conservatively around 40-50x my display volume. For me, using more flow decreases the chances of algae on my gorgs and the goni and acros grow faster For me.
I also Have not noticed a negative effect on my euphylia.

We often hear low, medium, high flow. But each person has their own idea of what each mean. I assume I have medium flow in my tank but another person may say it’s high flow. Measuring definitely is a tough task.
 
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I agree that flow is something we rarely talk about and it is extremely important. There are very few tanks with proper flow and if you SCUBA dive, especially around shallow reefs you will see that no matter how large our pumps, we won't be able to duplicate flow on a reef.

Even where waves are crashing corals are growing. I am not sure how they do it and it would give me a headache.

In my own tank I just installed one of those powerheads that is a foot long and spans almost the entire side of my tank. I can't turn it up full speed or it would splash all the water out of my tank.

My arrow crabs are holding on for dear life with one claw and shooting me dirty looks.
But with his other claw, he still manages to grab some lunch.

My Fireclowns are still spawning even though the current won't allow them to stay near their nest. But they manage to get up spurts of sped to do it.

My corals are all really loving it but the bristle worms keep getting knotted up with each other. :rolleyes:

High current is the way to go for "most" creatures.
If the ocean currents bothered anything, they’d all die. I have dived enough to know that the ocean is a constant current. An MP40 can’t stand next to a wave in the ocean.
 

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If my leathers are sulking I know my crossflow pump needs cleaning. If it’s before maintenance day then I’ll just crank the power up. Usually my pulsing Xenia is a good indicator of flow. If I can see it pulsing then the flow has slowed down.
 

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Perhaps part of the reason is because it's incredibly difficult to get a good gauge of someone's flow without a video. You could have the same exact equipment but completely different flow patterns depending on pump placement or aquascape. So while someone's issue may be flow, it would be awfully hard to verify it in a forum environment. Most other things we can quantify better.
 
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Perhaps part of the reason is because it's incredibly difficult to get a good gauge of someone's flow without a video. You could have the same exact equipment but completely different flow patterns depending on pump placement or aquascape. So while someone's issue may be flow, it would be awfully hard to verify it in a forum environment. Most other things we can quantify better.
I agree! A reefing buddy of mine said he had high flow in his tank, went there and he had only a return on his RS reefer 650. I couldn’t believe my eyes. No gyres even for such a large tank. Very hard to verify. I tend to lean on higher flow vs lower for any tank. If anything is obviously being beat up, redirect or decrease flow.
 

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We often hear low, medium, high flow. But each person has their own idea of what each mean. I assume I have medium flow in my tank but another person may say it’s high flow. Measuring definitely is a tough task.

That's why I let my corals decide what is best. I did notice reduced flow on one side of my tank plus I was getting more algae at the time. It was time for a pump cleaning.
 

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I think the big thong with flow is this, you can move alot of water with garden hose jet nozzle or you can move alot more water with a firehose and less pressure...

My point is that flow is very important but it's more important the type of flow. Those powerheads that create that jet of water will just rip LPS and some sps apart. But its important to move the water volume to move food, clear detritus, and remove toxins.
 
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ScottR

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I think the big thong with flow is this, you can move alot of water with garden hose jet nozzle or you can move alot more water with a firehose and less pressure...

My point is that flow is very important but it's more important the type of flow. Those powerheads that create that jet of water will just rip LPS and some sps apart. But its important to move the water volume to move food, clear detritus, and remove toxins.
I agree. It’s about water movement. You can’t direct flow through a noodle.
 
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