maximum flow through a refugium
- Thread starter hondo
- Start date
nm reef
Active Member
It would be difficult to say that there is a specific max or min flow rate.There are some systems where the refugium is a part of the sump and the flow rate is high...others like myself have free standing refugiums independant of a sump and the flow rates can be kept low(mine in about 100 GPH).
It all comes down to what you expect your refugium to provide for your system.Personally I wanted a refugium that provided increased water volume...would function as a sort of macro algae filter...would provide a predator free area for growth of micro fauna...would allow easy export of macros for nutrient export. I intentionally kept the flow rate low with the intention of providing longer contact time for the macro algaes to do their thing....and the system I use has been extremely effective for my system.
It all comes down to what you expect your refugium to provide for your system.Personally I wanted a refugium that provided increased water volume...would function as a sort of macro algae filter...would provide a predator free area for growth of micro fauna...would allow easy export of macros for nutrient export. I intentionally kept the flow rate low with the intention of providing longer contact time for the macro algaes to do their thing....and the system I use has been extremely effective for my system.
hondo
Member
NM,
What I am looking to do is run this reef skimmerless so my refugium would be my main filtration along with DSB and LR. My question really is about how much flow can I have through the refugium before the rate of flow decreases the effectiveness of the refugium. To get 10 - 15x flow in this tank I was looking to go with 2 hagen 802 in the display (or do a closed loop with a different style pump) and a mag 9 return from the refugium. I am worried that the mag 9 will be too much flow and will lower the effectiveness of the refugium. If it is then I could add a sump to handle the return and feed the refugium out of the sump with a smaller pump, using a gravity return from the refugium to the sump. So it's back to the original question for maximum filtration value what is the maximum flow rate for a 40g refugium.
What I am looking to do is run this reef skimmerless so my refugium would be my main filtration along with DSB and LR. My question really is about how much flow can I have through the refugium before the rate of flow decreases the effectiveness of the refugium. To get 10 - 15x flow in this tank I was looking to go with 2 hagen 802 in the display (or do a closed loop with a different style pump) and a mag 9 return from the refugium. I am worried that the mag 9 will be too much flow and will lower the effectiveness of the refugium. If it is then I could add a sump to handle the return and feed the refugium out of the sump with a smaller pump, using a gravity return from the refugium to the sump. So it's back to the original question for maximum filtration value what is the maximum flow rate for a 40g refugium.
sgt__york
Member
If i can ask.. you mentioned you had your refugium as a standalone system -- but I assume it's tied into the primary tank - else it wouldn't be acting as a filter
HOW do you have it setup?
I've head the best way is to have it pumped from the sump to the refugium (or use the existing primary tank sump and T it off w/a control value to reduce the incoming flow rate)...
As far as return - i've heard it's then best to have the refugiums overflow go INTO the main show tank - where the tank can receive the benefit of the the refugium. If it goes back to the sump - it's split as to whether it reaches the tank in any given amt (or returns to the refugium again) (or is this really much of an issue)?
I'm curious how you setup the pumps without having to set the refugium ABOVE the show tank (which is not always feasible structurally and aestetically) - and still ensure that power going off doesn't create floods.
HOW do you have it setup?
I've head the best way is to have it pumped from the sump to the refugium (or use the existing primary tank sump and T it off w/a control value to reduce the incoming flow rate)...
As far as return - i've heard it's then best to have the refugiums overflow go INTO the main show tank - where the tank can receive the benefit of the the refugium. If it goes back to the sump - it's split as to whether it reaches the tank in any given amt (or returns to the refugium again) (or is this really much of an issue)?
I'm curious how you setup the pumps without having to set the refugium ABOVE the show tank (which is not always feasible structurally and aestetically) - and still ensure that power going off doesn't create floods.
hondo
Member
sgt york,
I haven't actually set this system up yet but it will be tied to the main tank. The tank has two corner overflows which will lead to either a sump or directly to the refugium, depending on how much return flow I can have.
On my 50g reef I use a 10g sump and a life reef overflow to get the water from the display to the sump. I then have my skimmer and heater in the sump along with a mag 7 return pump which feeds a spray bar along the back of the tank (all this is DIY and very simple to do). I use a MJ 600 to feed the refugium out of the sump and a simple siphon tube for the return from the refugium to the sump. So basically water flows from the life reef overflow to the sump where it is skimmed and some is sent to the refugium and returns to the sump and is returned to the main via the mag 7. Don't worry about pods going through the return pump as they rarely get damaged and if they do they are just instant food upon return to the main. I see pods (mainly mysid shrimp) getting sucked into my seaclone skimmer and swimming aournd inside the bubble chamber all the time. So if the trip through the mj1200 doesn't hurt them then neither does the mag 7.
As for floods well that is why I bought the life reef. I have tried turning my pumps off to get a flood going and it just doesn't happen as the life reef will only deliver the same amount of water to the sump as the sump is pumping to the tank when the pump stops so does the life reef. You just have to remember to put a siphon break somewhere on your return line or the flood will happen when the pump goes off and the return line siphons back into the sump. As for the life reef losing siphon this just doesn't happen unless the tube is lifted out of the unit. air does not build up in the tube as any flow rate above 350gph or so pulls the air right through the siphon tube. Just clean it every so oftern as algae builds up on it (it's clear plex) and it's problem free.
I haven't actually set this system up yet but it will be tied to the main tank. The tank has two corner overflows which will lead to either a sump or directly to the refugium, depending on how much return flow I can have.
On my 50g reef I use a 10g sump and a life reef overflow to get the water from the display to the sump. I then have my skimmer and heater in the sump along with a mag 7 return pump which feeds a spray bar along the back of the tank (all this is DIY and very simple to do). I use a MJ 600 to feed the refugium out of the sump and a simple siphon tube for the return from the refugium to the sump. So basically water flows from the life reef overflow to the sump where it is skimmed and some is sent to the refugium and returns to the sump and is returned to the main via the mag 7. Don't worry about pods going through the return pump as they rarely get damaged and if they do they are just instant food upon return to the main. I see pods (mainly mysid shrimp) getting sucked into my seaclone skimmer and swimming aournd inside the bubble chamber all the time. So if the trip through the mj1200 doesn't hurt them then neither does the mag 7.
As for floods well that is why I bought the life reef. I have tried turning my pumps off to get a flood going and it just doesn't happen as the life reef will only deliver the same amount of water to the sump as the sump is pumping to the tank when the pump stops so does the life reef. You just have to remember to put a siphon break somewhere on your return line or the flood will happen when the pump goes off and the return line siphons back into the sump. As for the life reef losing siphon this just doesn't happen unless the tube is lifted out of the unit. air does not build up in the tube as any flow rate above 350gph or so pulls the air right through the siphon tube. Just clean it every so oftern as algae builds up on it (it's clear plex) and it's problem free.
jumpfrog
Active Member
sgt-york, like hondo I use a PH to return water back to the main tank. I too use a life reef overflow. The overflow will only drain to the refugium as much water as comes in so your PH determines your flow rate. I'm using a MJ 1200 pushing up about 4.5'. Probably only getting 75-80 gph. Only problem I have is that the flow rate isn't high enough to keep the life reef "air free". As a result I have to reprime about every 2 weeks. No biggie as it only takes a few seconds. As hondo said, don't forget to create a break in your return. I just drilled two 1/16" holes just above the return outlet. Water drains about 1/2 to 3/4 gallon before the back siphon breaks.
Good Luck!
Good Luck!
broomer5
Active Member
This is my opinion on flowrates through an algae planted refugium.
You want the flow to be low enough so you don't blow your sand around, and tear up your plants. That's it.
Again in my opinion, in a closed loop system - the algae do not reguire a retention time for them to take in nutrients and CO2 gas. They are going to do this whether the water is barely moving or if it's rushing past them. As long as they have access to the water, and have adaquate lighting - they will do what they do - flowrate not near as important as many seem to believe.
It's just like water passing by a protein skimmer or even water passing past (around) a heater. We're not batch processing this volume of water, it's a continuous flowing loop.
The skimmer will skim what it can - the rest goes on past.
The algae will take in what it can, give off what it will, and the rest will flow on past - only to come around again some time later for another pass. I'm talking molecular here - not visible to the eye stuff.
As far as I'm concerned, as long as the alage is in the system and is growing - flowrate has little to do with how effective it does it's job.
Naturally you don't want water rushing through the refugium so fast that you stir everything up and create a fine particulate dust cloud in your display tank, but any flowrate below that is fine IMO.
On the other hand - having too low a flowrate of water through the refugium can hamper the algae effectivness at removing nutrients, exchanging gases, and if too low - there's a possibility of the stuff dying. A stagnent green or cyno mess may follow soon thereafter, with a different refugium water chemistry compared to that of your display tank.
If I am misinformed on this - please someone redirect me to a study or article that explains refugium flowrates in greater detail.
I would appreciate the information a lot, and I'm always willing to learn from the pro's.
You want the flow to be low enough so you don't blow your sand around, and tear up your plants. That's it.
Again in my opinion, in a closed loop system - the algae do not reguire a retention time for them to take in nutrients and CO2 gas. They are going to do this whether the water is barely moving or if it's rushing past them. As long as they have access to the water, and have adaquate lighting - they will do what they do - flowrate not near as important as many seem to believe.
It's just like water passing by a protein skimmer or even water passing past (around) a heater. We're not batch processing this volume of water, it's a continuous flowing loop.
The skimmer will skim what it can - the rest goes on past.
The algae will take in what it can, give off what it will, and the rest will flow on past - only to come around again some time later for another pass. I'm talking molecular here - not visible to the eye stuff.
As far as I'm concerned, as long as the alage is in the system and is growing - flowrate has little to do with how effective it does it's job.
Naturally you don't want water rushing through the refugium so fast that you stir everything up and create a fine particulate dust cloud in your display tank, but any flowrate below that is fine IMO.
On the other hand - having too low a flowrate of water through the refugium can hamper the algae effectivness at removing nutrients, exchanging gases, and if too low - there's a possibility of the stuff dying. A stagnent green or cyno mess may follow soon thereafter, with a different refugium water chemistry compared to that of your display tank.
If I am misinformed on this - please someone redirect me to a study or article that explains refugium flowrates in greater detail.
I would appreciate the information a lot, and I'm always willing to learn from the pro's.
nm reef
Active Member
Hondo ...it sounds to me like you have a great plan for your system. The advice from broomer is good stuff. I agree that to a certain extent flow rate may have little bearing on the effectiveness of a refugium.
I might add that my reef has been skimmerless for over a year now...just my refugium/DSB/LR for filtration. For me it has worked extremely well...but I do have some concerns about long term lack of a skimmer. For that reason I have plans to modify my current filtration and include a large capacity skimmer.
What you are planning is close to what my final system will be. Let me explain...possibly my plans combined with yours will help us both. First I have a 55 gal reef that has a 70 gal refugium . My refugium is fed via 2 Hagen 802 powerheads...and currently the flow rate is about 100 GPH. My intention when developing my refugium was to increase water volume/provide safe environment for growth of micro fauna/grow & harvest macro algae...plus I wanted my refugium to be independant of future plans for a sump & I wanted it to be gravity returned to the display. All of my objectives have been met and my refugium is now fully developed. It is in my opinion a vital step in a long range plan for the filtration/circulation system of my reef.
I am soon installing a 29 gal sump with a top quality skimmer and a return pump that will allow the removal of all powerheads from my reef and at the same time increase circulation drastically. When this project is complete I will still have my refugium independant of the sump and it will still gravity return to the display. My plan is to continue feeding water to the refugium via the Hagen 802's...but after the sump is in place the water will feed from the sump to the refugium. Follow me. I feel that for my system the gravity return is the best option....plus for me it is possible due to the benefit of being able to have the sump & refugium remote in the back room...directly behind the display. Personally I feel that it would be a benefit to have the refugium seperate from the sump and returned via gravity at a much lower rate than the sump returns.
I may be going about this backwarrds of most folks...but after the sump is in place and the 55 reef settles back down ... then I have plans to remove the 55 and replace it with a 150 with dual overflows. At that time I will either include a second 29 gal sump...or a closed loop system to increase circulation for the larger volume display.
Bottom line I'd prefer a low flow rate gravity reutrned refugium over one that is a higher flow and returns via pumps from the sump...IF it is possible.
But....any refugium that is mature/stable will be a benefit....and the actual flow rate will have little to do with how effective it is.As stated just keep the flow low enough to avoid disturbing either the sand or the macros.....I personally prefer a slower rate...but higher flows also are effective!
I might add that my reef has been skimmerless for over a year now...just my refugium/DSB/LR for filtration. For me it has worked extremely well...but I do have some concerns about long term lack of a skimmer. For that reason I have plans to modify my current filtration and include a large capacity skimmer.
What you are planning is close to what my final system will be. Let me explain...possibly my plans combined with yours will help us both. First I have a 55 gal reef that has a 70 gal refugium . My refugium is fed via 2 Hagen 802 powerheads...and currently the flow rate is about 100 GPH. My intention when developing my refugium was to increase water volume/provide safe environment for growth of micro fauna/grow & harvest macro algae...plus I wanted my refugium to be independant of future plans for a sump & I wanted it to be gravity returned to the display. All of my objectives have been met and my refugium is now fully developed. It is in my opinion a vital step in a long range plan for the filtration/circulation system of my reef.
I am soon installing a 29 gal sump with a top quality skimmer and a return pump that will allow the removal of all powerheads from my reef and at the same time increase circulation drastically. When this project is complete I will still have my refugium independant of the sump and it will still gravity return to the display. My plan is to continue feeding water to the refugium via the Hagen 802's...but after the sump is in place the water will feed from the sump to the refugium. Follow me. I feel that for my system the gravity return is the best option....plus for me it is possible due to the benefit of being able to have the sump & refugium remote in the back room...directly behind the display. Personally I feel that it would be a benefit to have the refugium seperate from the sump and returned via gravity at a much lower rate than the sump returns.
I may be going about this backwarrds of most folks...but after the sump is in place and the 55 reef settles back down ... then I have plans to remove the 55 and replace it with a 150 with dual overflows. At that time I will either include a second 29 gal sump...or a closed loop system to increase circulation for the larger volume display.
Bottom line I'd prefer a low flow rate gravity reutrned refugium over one that is a higher flow and returns via pumps from the sump...IF it is possible.
But....any refugium that is mature/stable will be a benefit....and the actual flow rate will have little to do with how effective it is.As stated just keep the flow low enough to avoid disturbing either the sand or the macros.....I personally prefer a slower rate...but higher flows also are effective!