Flow Rate Low verse High

So I'm about 2 months into my second saltwater tank and I have a few questions concerning the viability of a complete nutrient transport refugium. Before I get to my question here's my set up thus far.

My tank:
55 Gallon Reef Style
25 lbs LR
3 inch Sand Bed
Radion 15 pro LED
2 clowns and 1 Lawnmower Blenny
Mixed variety clean up crew.
I use Chemi pure Elite, Purigen, Phosguard.

HOB 5 gallon refugium (chaeto, Seachem Matrix, Fiji mud, 24/7 LED)

10 gallon sump refugium (calerpa, dragonsbreath, Fiji mud, 24/7 CF, 630 Gph pump realistically around 450GPH. )

Both refugiums have been stocked with tiger pods, tisbe pods, and live phyto feast.

Now my question is that given my current set up do you feel this will be sufficient for complete nitrate and Phosphate transport/uptake?

If not what would you change?

Also I'd like to know if you are running such a refugium filtration system what yours is like? (Gallon Size, Flow rate, Algae, Substrate.)

 

Welcome to 3reef, excellent beginnings.

Nothing can really equal a tank that has had a chance to fully cycle and become established. You're tank is very young, you've provided it with the essentials, and done your homework, now just let the tank and filtration establish a sufficient biological filter.

You'll eventually want more rock and another or larger lighting fixture. Until that time you can stock slowly to allow the bacteria to grow with each new addition.

 

Thanks for the input. I plan on setting up the left side of the DT the same as the right after my tank does a bit of maturing. Plus it will take a while to save up for another radion light & 30 lbs of LR.

Prior to this tank I had a 60 gallon cube for around a year and a half.

 

I'll for sure be following your progress. I haven't seen much on the results of using mud. I'd say you have as good a chance as any to have a complete nutrient export system. In also interested in seeing how well the pods do. Is it your plan to have them feed the tank in order to have a self sufficient system? Also, what do you plan for water changes?

 

The appeal of an ecosystem style filtration system was two fold for me. One being a means to naturally filter nitrates and phosphates/detritus and the other to be an ideal growing location for microorganisms that would filter back into my display tank to feed my corals.

In the bottom refugium we have a high flow rate (450) that feeds back into my DT via a pump. And in my HOB refugium we have a slow flow rate (80gph) that feeds back to my DT via overflow manifold.

It'll be interesting to see how the pods develop in each style.

Also this leads me to the title of my post. High Flow rate verse Low Flow rate. I've read some posts on here claiming the benefits of slow flow however the idea for this style of filtration first came to me from Leng Sy who supports high flow.

So I'm not sure which way I would benefit from more and thus ended up doing both.

 

I think that it is important to remember that no matter how well we build our systems, they are still artificial ecosystems that require outside input to maintain. My understanding of the thought process of low flow through a refugium is to increase dwell time of the water within the system to maximize nutrient removal. This sounds good on the surface, however the system contains a finite amount of water that will all flow through the refugium and be available to have its nutrients exported. As for pod production, in do not know how flow would effect that. Im sure that this will develop into a robust discussion!

 

I've heard as well that the slower flow rate allows for higher dwell times for nutrient absorption. However if all the water in the tank has equal amounts of nutrients to absorb I fail to see how dwell time would matter. Unless that is to say macro algae absorb more efficiently in slower flow rates than they do in higher flow rates?

 

I don't know of any research that shows that algae absorbs better at lower flow rates. The only issue I can see for higher flow rates would be pod production. Someone else can probably speak to this issue much better than me. All that being said, many if not most people have lower flow refugiums and clearly they have worked well. My assumption is that it is a matter of personal preference. Perhaps if you build one capable of high flow and is adjustable you could do your own research and post the results for all of us to see!!