Turbulent Flow vs Laminar or Circular Flow patterns

Punchanello · Mar 4, 2019

I was hoping to get some thoughts from our experienced reefers on their preferred way of applying flow to an SPS reef.

I started by running two Tunze 6105s . I felt like I had enough total flow with the 6105s for the moment (I still have a lot of rock to fill with corals) but I din't think I had enough flow hitting specific parts of the tank. So I have now ordered wo additional 6095s which will give me a total maximum of of 90x flow (not including the return).

I've noticed a lot of VorTech users prefer random and turbulent flow. On the other hand Tunze suggests a circular flow - This is from their Smartcontroller Manual -

"The interval operation between low tide (channels 1 and 2) and high tide (channels 3 and 4) enables the creation of two annular flows in the aquarium. The reef rock is regularly flooded from both sides, the sediments are washed away and the invertebrates exposed to current from all directions. "

This is a graphic from their 2019 catalogue -

I have the capacity to implement the Tunze approach now with four Turbelle pumps and the Smartcontroller. I can also simply aim for turbulent flow.

I'm wondering what our experienced SPS keepers think about the pros and cons of each approach?

K-Philly · Mar 4, 2019

I won't be as bold to say I am "experienced," in the way of SPS keeping, but if I may, I can see the reasons of why the goal would be to be more circular. To me, it seems like it is mimicking a natural wave. Because waves "roll," in a circular motion. Thus, you have a more even flow. One reason why I decided to move away from the individual powerheads is because I was dealing mainly with the AC setups. If I am not mistaken, AC is your one way only turn of the propellers, and DC is the ability of the propellers to spin forward and reverse. Allowing "pulsing," which can push and pull water like a wave.

I'm almost 90% sure that's exactly what my Comline Wave box does. I went with it on my 6ft tank because I am no good with sticking powerheads everywhere in order to achieve balance. I also wanted less of my equipment in the actually DT when possible. For the health of the corals, I think it is very possible to achieve balance through randomization. However, I can also see that becoming quite difficult when you get into the 6ft range. I can see that you mentioned that you have a controller, so obviously the pumps you are using are DC. I wanted to mention AC just in case anyone who stumbles upon this thread can also learn from it, if AC is what they are doing.

From my understand, on a very basic level, we need plenty of flow and basically we just want water to "weave," back and forth among the coral. Not to lightly but not to harshly. I have seen some corals such as hammer corals, get blasted by water like some water-bender was mad at them. I jsut could not see how that was healthy and didn't cause physical damage. I feel even with SPS there are some good general guidelines. Even if I am wrong, I will be more than happy to admit it. I am posting an article published by Standford University. Check it out, and tell me what you think. I found it interesting.

https://engineering.stanford.edu/ma...e-dynamics-and-water-flows-affect-coral-reefs

NewbsReef · Mar 4, 2019

I'm gonna stick around and follow this thread.

I by all mean am no expert in this hobby amd i still learn every day. On my 40 breeder i have a power head on each side of the tank but not directly pointing at each other. So front and back i have a circular flow and in the middle of the rock work i get a turbulent flow. I mainly house SPS up high and a 3 big duncan colonies on the sand and they don't get blasted. Everything seems happy.

NewbsReef · Mar 4, 2019

jda · Mar 4, 2019

I don't think that it matters as long as it is somewhat random and not the same way all the time. If you keep it the same way all the time, the corals will start to "lean" that way as they grow.

Flow is hard to screw up as long as you have it. Those 6105s can be used in any configuration and be fine, IMO.

You might find people who like one type over another and swear that this worked better for this. You can find enough people on all sides. What probably happened is that what they liked was probably what they were using when their tank "came together" and it was a culimation of things and not just the flow that mattered.

FWIW - I use a pair of 6105s and a Tunze Wavebox on a 240g and it is enough flow. Some people use 10x more than this without any better results.

K-Philly · Mar 4, 2019

I agree with the above statement as well, and that’s why I think it’s so important to research and learn what your specific needs or preferences are. Facts are facts, because someone or a group of people tested a hypothesis and found evidence of an event occurring or not occurring. It’s accepted because everyone involved in testing that hypothesis agree that what they are finding is true. Or they agree for the most part.

I find trying to stick as close to natural and balance as best as possible, is a good route for me.

Punchanello · Mar 4, 2019

jda said:
FWIW - I use a pair of 6105s and a Tunze Wavebox on a 240g and it is enough flow. Some people use 10x more than this without any better results.

Wow! On a 240g?!

SeaDweller · Mar 5, 2019

Punchanello said:
Wow! On a 240g?!

I use 2x 6105 2 x 6095 1 Gyre 250 and two eductors. I was using VCA random flow generators but they were so weak. This is on an 8’ 240 as well. Tunzes run full blast

Vahanyos · Mar 5, 2019

I currently have a 42g and it’s SPS dominant (acros, Millie’s, stags, monticap, Birdsnest), and what works for me is I have an mp10 on the right side on reef crest 100% power (which goes from like 100 gph to 1500gph), one jebao RW4 on the back glass (Ramps up and down from 100gph to 1000gph), and my return which probably produces around 700 gph. I have them all pointed to the middle of the tank. The flow is not calculated by how much turnover or gph’s I have, but rather how the corals get hit with the flow. I was able to achieve turbulent random flow where they are getting hit from top, bottom, left, right, etc... polyps are swaying in every direction rapidly but not directly blasting the corals either. They love it. People were saying it’s not enough flow and to add another power head in there, but it’s not necessary because they are growing nice and bushy and thriving.

I’d go with turbulent random flow any day.

rockskimmerflow · Mar 5, 2019

jda said:
I don't think that it matters as long as it is somewhat random and not the same way all the time. If you keep it the same way all the time, the corals will start to "lean" that way as they grow.

Flow is hard to screw up as long as you have it. Those 6105s can be used in any configuration and be fine, IMO.

You might find people who like one type over another and swear that this worked better for this. You can find enough people on all sides. What probably happened is that what they liked was probably what they were using when their tank "came together" and it was a culimation of things and not just the flow that mattered.

FWIW - I use a pair of 6105s and a Tunze Wavebox on a 240g and it is enough flow. Some people use 10x more than this without any better results.

I agree flow is a pretty forgiving parameter. In fact, I'm not even sure it matters all that much if it's the same way all the time. In my systems I run almost exclusively on eductors pushing gyres in one direction continuously these days and yeah the coral will lean at first but it doesn't seem to suffer at all once established. Coral placement is somewhat dictated by this scheme with regard to how much velocity its tissue can take continuously, but I've found that once the coral figures out the flow it will lean into it initially and then proceed to take on a more typical colony shape. I wasn't sure if this would work long term, but I haven't encountered any corals in the past year since I removed all my wavemakers that have suffered from not having randomized or sometimes reversed gyre flow. It really is a lot harder to screw up flow I'm finding out the more I try and simplify my husbandry approaches. I almost wonder now if a gyre that reverses every so often is the pinnacle of flow execution or if a randomized pulsating and ramping wavemaker type scheme is 'better' for the majority of corals. Corals seem to really prefer it if stuff isn't too variable within their environment all the time so I do wonder if they actually need something so random as the insanely customizable options we have nowadays on the DC prop pumps.

It wasn't like the early successful SPS guys grew their massive colonies on anything more than closed loops and AC propellor stream pumps.