ccombs
Valuable Member
First off, if you want great information on flow, please see this article!
https://www.reef2reef.com/threads/i...d-powerheads-for-the-reef-tank-part-1.572239/
This answers all of the questions we are too afraid to ask and is a way better resource than what I am writing.
This post is more of a community discussion and my thoughts on flow, much like my previous write up on my theory of overstocking. https://www.reef2reef.com/threads/my-theory-on-overstocking.568593/
I would love to hear from others and discuss other viewpoints and challenge ourselves here.
Without any further delay, let's discuss flow!
I have always thought my tank seemed turbulent. At first look, it appeared I had proper flow. My tank came with a return pump of around 450 gallons, and my tank is only 30 gallons, so 15x turnover.
After some time, I realized that I had great surface agitation, but the water near the bottom of the tank was pretty stagnant. This pushed me to purchase an Icecap 1k gyre which I really like. However, I felt like I could only run it at 10%-20% before it looked like my fish were weather channel reporters.
This was unfortunate because my gyre couldn't really gyre, if you will. My gyre became a glorified powerhead.
I lived with this reality for awhile, but I knew it had to be stressful on fish to live in a hurricane 24/7. As fate would have it, I had to breakdown my tank anyway for other unforeseen reasons, and this gave me a chance to address my issues.
First thing I did was purchase 2 return pump that were DC controllable. This did 2 things. First, it allowed me to have redundancy if one failed. Second, it allowed me to dial in the speeds of the pumps so I could optimize flow.
When I went to re-fill the tank, it gave me a chance to learn something new, how much water my tank actually had with all of the rock, etc. I had estimated it actually held 25 gallons, but to my surprise it only holds 18-19 gallons with everything in there. I started looking at my gear and realizing if I ran everything at 100%, I had over 2100 GPH of flow. For those of you following along at home, that is over 100x turnover in the tank........I can tell you, too much flow is possible.
In my quest for proper flow that my corals would love down the line, I started working to dial in the flow. As fate would have it, I had to re-break in my skimmer, so I just ran it with my cup off. This, in turn, created micro bubbles. These micro bubbles actually gave me the unique opportunity to see my flow and how the sine wave pumps and my gyre all interacted. Since this discovery, I have been able to play around with flow rates and patterns, and dial in a mix of pumps that give me changing flow with very few dead spots in the tank. My strategy is to use the gyre to create flow across the top of my tank (a wave essentially) that is unimpeded by the rocks/etc. Then it returns near the bottom where it starts to have obstacles. This now allows me to direct my return pump nozzles in such a way to fill in these gaps. Interestingly enough, I created a water tornado by aiming a pump too close to the flow of my gyre, it was actually quite funny.
Now, my tank experiences slower flow per source, but it is well distributed and have no dead spots.
Why have I told you all of this? Do I like writing? - not necessarily. Do I love random anecdotes? - no, they can be a time waster. I wrote this so maybe someone can learn from my mistakes and try out my theory on flow, which is this... Well distributed, slowly changing flow patterns are a key to a success. Just like testing water, do not shoot for a certain GPH turnover and call it a day. Chasing numbers is the enemy of what we are doing here. Understand why you should have a certain turnover. I theorize that well distributed, lower flow environments are better than a numerically perfect turnover from fewer, more turbulent, sources.
https://www.reef2reef.com/threads/i...d-powerheads-for-the-reef-tank-part-1.572239/
This answers all of the questions we are too afraid to ask and is a way better resource than what I am writing.
This post is more of a community discussion and my thoughts on flow, much like my previous write up on my theory of overstocking. https://www.reef2reef.com/threads/my-theory-on-overstocking.568593/
I would love to hear from others and discuss other viewpoints and challenge ourselves here.
Without any further delay, let's discuss flow!
I have always thought my tank seemed turbulent. At first look, it appeared I had proper flow. My tank came with a return pump of around 450 gallons, and my tank is only 30 gallons, so 15x turnover.
After some time, I realized that I had great surface agitation, but the water near the bottom of the tank was pretty stagnant. This pushed me to purchase an Icecap 1k gyre which I really like. However, I felt like I could only run it at 10%-20% before it looked like my fish were weather channel reporters.
This was unfortunate because my gyre couldn't really gyre, if you will. My gyre became a glorified powerhead.
I lived with this reality for awhile, but I knew it had to be stressful on fish to live in a hurricane 24/7. As fate would have it, I had to breakdown my tank anyway for other unforeseen reasons, and this gave me a chance to address my issues.
First thing I did was purchase 2 return pump that were DC controllable. This did 2 things. First, it allowed me to have redundancy if one failed. Second, it allowed me to dial in the speeds of the pumps so I could optimize flow.
When I went to re-fill the tank, it gave me a chance to learn something new, how much water my tank actually had with all of the rock, etc. I had estimated it actually held 25 gallons, but to my surprise it only holds 18-19 gallons with everything in there. I started looking at my gear and realizing if I ran everything at 100%, I had over 2100 GPH of flow. For those of you following along at home, that is over 100x turnover in the tank........I can tell you, too much flow is possible.
In my quest for proper flow that my corals would love down the line, I started working to dial in the flow. As fate would have it, I had to re-break in my skimmer, so I just ran it with my cup off. This, in turn, created micro bubbles. These micro bubbles actually gave me the unique opportunity to see my flow and how the sine wave pumps and my gyre all interacted. Since this discovery, I have been able to play around with flow rates and patterns, and dial in a mix of pumps that give me changing flow with very few dead spots in the tank. My strategy is to use the gyre to create flow across the top of my tank (a wave essentially) that is unimpeded by the rocks/etc. Then it returns near the bottom where it starts to have obstacles. This now allows me to direct my return pump nozzles in such a way to fill in these gaps. Interestingly enough, I created a water tornado by aiming a pump too close to the flow of my gyre, it was actually quite funny.
Now, my tank experiences slower flow per source, but it is well distributed and have no dead spots.
Why have I told you all of this? Do I like writing? - not necessarily. Do I love random anecdotes? - no, they can be a time waster. I wrote this so maybe someone can learn from my mistakes and try out my theory on flow, which is this... Well distributed, slowly changing flow patterns are a key to a success. Just like testing water, do not shoot for a certain GPH turnover and call it a day. Chasing numbers is the enemy of what we are doing here. Understand why you should have a certain turnover. I theorize that well distributed, lower flow environments are better than a numerically perfect turnover from fewer, more turbulent, sources.
