How does MORE flow affect coral growth? | BRStv Investigates

[randyBRS]

It's finally here Reefers!


Today we've got our first look at the results from our Flow Tank testing we've been doing for the past 4+ months! Pretty interesting!

 

[Crabs McJones]

Another great video @randyBRS
Very informative, time to go home and mess with some powerheads

 

[Max!]

Great stuff!

 

[Greaps]

I have a different conclusion following this test. If corals grew 5% more in mass over two months, compound that +5% over 12-24 months and we have a much larger coral in the end. Plus corals growth would disrupt that flow more and more over time and require more and more total tank turnover to get around it.

Good test guys. Thank you.

 

[motortrendz]

I have found over the years that higher flow creates a denser coral. I've noticed it extreme on anacropora. I have one I pray direct flow from my mp40 and it has grown a dense crown bushy look. And another which is in indirect flow and it has grown in an open longer branching pattern.

 

[Sailingeric]

I replaced my cheap powerhead with a Nero 5 set to do random flow in my 75 gallon tank and my hammers have gotten a lot bigger. Not sure it is increased flow or wave action but I saw results in a couple weeks.

 

[TexasTodd]

Thanks again! I've wondered how Dana's study on IPS of current convert to tank turnover.

 

[mr9iron]

Thanks for taking the time to do the flow study. I enjoy watching your videos and appreciate the time and resources you put into making the reef community better.

 

[Charlie’s Frags]

Awesome video. I’ve had the same experience in my tank. My sps that are in high flow areas encrust more and branch away from the current and my sps in lower flow areas have more vertical branching growth.

 

[aarbutina]

While watching this video I realized that there may be a slight flaw (by design) in your experiment. The problem I see is that the high flow and low flow tanks are separate systems with distinct water chemistry and as much as you try to keep them aligned they are still going to be different. At this point you are testing the impact of flow and water chemistry on the system. To truly test flow only you would need to tie the two systems together and then measure coral growth based on weight/mass alone.

I am sure this point was considered when designing the experiment and there was probably a rational for why you choose to do it the way you did. But just wanted to point out what we have here isn’t really a univariant study design.

 

[7237689918]

I think the value is that it's a pretty controlled test. For us, there are so many factors that could skew the results and difficult to draw any conclusions. My corals suck with low or high flow, so I see the same results of the test!

 

[Brew12]

I know this is a bit older but I finally watched it this weekend. It points out what I feel is a big comprehension issue when it comes to flow. The most important flow number is velocity at the coral/water interface. The volume of water being moved is irrelevant. You can put 2 MP40's side by side and move much more water but it won't necessarily increase velocity. In an actual reef tank it would likely increase velocity to some corals but as shown, it is a minimal impact in a frag tank.

I think this test would have been much more interesting using gyre pumps. The MP40's have very diffused flow so increasing the speed has a lessor effect on velocity. Gyre pumps are all about velocity. Run one system with a gyre at 30% and another with the gyre at 70%. That would be a significant change in velocity which I believe will translate into better coral growth.

 

[Max93]

Should do this same exact test, except with metal halides.

 

[slingfox]

Should do this same exact test, except with metal halides.

This is a 5 year old thread. BRS doesn't have any interest in running any tests on metal halides since they don't sell them and halides have a continually diminishing presence in the hobby.