Airlift circulation/airlift surge ???
- Thread starter Agu
- Start date
piercho
New member
I've built a combined airlift and RCSD surge for a 65G tank. I put it on my reef tank about 12 days ago and ran it for 9 days with what I percieved as very good results: better gas exchange than I had before [pH nominal at 8.11 with about +/- .07 variance over a day (this is using limewater for make-up)]; coral showing better polyp extension and all inverts showing strong and consistent feeding responses. I took the system offline 3 days ago to modify where I vent air and will restart it this evening.
The b*tch is I have a good Visio diagram of the system that I can convert to .gif but RC won't let me post it because of it's dimensions. When I try to "shrink" the image the resolution gets so crappy it is not worth posting.
"A quick search brought up no information. "
Jon (Snailman) was kind enough to send me a Sea Scope article on one guy's experience with a great big honking Reverse Carlson Surge Device (RCSD) mounted inside a tank. Basically, instead of having a container above the waterline like a conventional surge device, a RCSD is mounted below the waterline. I can't find the article at this moment. If you'd like, I could gen a rough diagram and post it. The article goes into great detail of the trials and tribulations of trying to use an in-tank RCSD.
"How does it work ? "
In this article, the guy hooked the air supply driving the RCSD common to air lifts. The air supply pressure will vary as the RCSD vents and refills. So, the air-lifts will turn off and on as the RCSD vents and refills. Air-lift water flow will be maximum at the moment before the RCSD vents.
My design works on this concept, except, my lift and RCSD are mounted externally, not internally. With these items mounted externally, I can control virtually all of the noise and salt spray associated with them. The downside is that the surge effect is dampened and the lift output is greatly reduced because of plumbing resistance.
"What are the positives and negatives ? "
Positives:
-Gas Exchange: I get better gas exchange (as measured by pH variance) with a lift than an equivalent amount of pump circulation.
-Safety/Reliability:I don't have any moving parts, or electricity, in the water for water circulation. I can run a surge without a valve and cycle a lift pump on and off without relays. The only moving part of the entire system is the piston in the pump.
-Effeciency: My water movement energy efficiency is better than sump + closed loop in my configuration. The propellor PH's (Tunze and ReefTec) are much better for energy effeciency. In-tank lifts would probably ace the propellor PHs but how would you deal with the spray?
-Adey speculates that you can maintain a more diverse population of plankters with non-tramatic pumps.
-Spotte provides other's research showing that lifts drive DOM->POM. Skimmers do this too, of course, except that the POM and maybe some plankters are removed from the system.
Negatives:
-No info: There is a dearth of information on building lifts. I used some Spotte references from the 1970s and my final flow was quite a bit different (more, thankfully) than projected.
-Noise: when I built the prototype my first reaction was THAT'S TOO DAMN LOUD!!!" The lift, the RCSD, the piston pump are all pretty loud. By tinkering/redesigning/rebuilding I got the noise way down. Also, I plumbed back through the wall and put them in a utility room closet. Now the tank is virtually silent. But, noise control takes some thought, effort, and design concessions to control.
-I've been researching and tinkering with this crap for over a year. I went through two test set-ups to feel confident enough to mount it. There was a lot of PVC/ABS work involved and I'm no plumber. You want flow? Buy a ReefTec. You want aeration? Plumb a sump and hook a gargantuan skimmer to it. Or, just bite the bullet and pay the $$$$$ for that wheeled-ATS air-drive thingy.
At some point I intend to post some pics and a diagram of this thing on the DIY board. Until then, I hope some small part of my rantings were useful.
The b*tch is I have a good Visio diagram of the system that I can convert to .gif but RC won't let me post it because of it's dimensions. When I try to "shrink" the image the resolution gets so crappy it is not worth posting.
"A quick search brought up no information. "
Jon (Snailman) was kind enough to send me a Sea Scope article on one guy's experience with a great big honking Reverse Carlson Surge Device (RCSD) mounted inside a tank. Basically, instead of having a container above the waterline like a conventional surge device, a RCSD is mounted below the waterline. I can't find the article at this moment. If you'd like, I could gen a rough diagram and post it. The article goes into great detail of the trials and tribulations of trying to use an in-tank RCSD.
"How does it work ? "
In this article, the guy hooked the air supply driving the RCSD common to air lifts. The air supply pressure will vary as the RCSD vents and refills. So, the air-lifts will turn off and on as the RCSD vents and refills. Air-lift water flow will be maximum at the moment before the RCSD vents.
My design works on this concept, except, my lift and RCSD are mounted externally, not internally. With these items mounted externally, I can control virtually all of the noise and salt spray associated with them. The downside is that the surge effect is dampened and the lift output is greatly reduced because of plumbing resistance.
"What are the positives and negatives ? "
Positives:
-Gas Exchange: I get better gas exchange (as measured by pH variance) with a lift than an equivalent amount of pump circulation.
-Safety/Reliability:I don't have any moving parts, or electricity, in the water for water circulation. I can run a surge without a valve and cycle a lift pump on and off without relays. The only moving part of the entire system is the piston in the pump.
-Effeciency: My water movement energy efficiency is better than sump + closed loop in my configuration. The propellor PH's (Tunze and ReefTec) are much better for energy effeciency. In-tank lifts would probably ace the propellor PHs but how would you deal with the spray?
-Adey speculates that you can maintain a more diverse population of plankters with non-tramatic pumps.
-Spotte provides other's research showing that lifts drive DOM->POM. Skimmers do this too, of course, except that the POM and maybe some plankters are removed from the system.
Negatives:
-No info: There is a dearth of information on building lifts. I used some Spotte references from the 1970s and my final flow was quite a bit different (more, thankfully) than projected.
-Noise: when I built the prototype my first reaction was THAT'S TOO DAMN LOUD!!!" The lift, the RCSD, the piston pump are all pretty loud. By tinkering/redesigning/rebuilding I got the noise way down. Also, I plumbed back through the wall and put them in a utility room closet. Now the tank is virtually silent. But, noise control takes some thought, effort, and design concessions to control.
-I've been researching and tinkering with this crap for over a year. I went through two test set-ups to feel confident enough to mount it. There was a lot of PVC/ABS work involved and I'm no plumber. You want flow? Buy a ReefTec. You want aeration? Plumb a sump and hook a gargantuan skimmer to it. Or, just bite the bullet and pay the $$$$$ for that wheeled-ATS air-drive thingy.
At some point I intend to post some pics and a diagram of this thing on the DIY board. Until then, I hope some small part of my rantings were useful.
Agu
Premium Member
Howard,
Thanks for the info but you're assuming I have some knowledge of the basic concepts. I understand from Jons pic here http://www.hawkfish.org/snailman/airliftpic.htm that air bubbles force water up the tube and circulates it. Is that correct? Does it move enough water to justify putting that big piece of pvc in the tank ? Obviously tube size and pump size are factors, do you need a huge airpump to make it work? What about salt spray?
BTW, I've built some surge devices, and the concept of putting it right in the tank sounds uhhhh unique. Of course mine were built out of garbage cans with toilet flappers :eek1: .
Agu
Thanks for the info but you're assuming I have some knowledge of the basic concepts. I understand from Jons pic here http://www.hawkfish.org/snailman/airliftpic.htm that air bubbles force water up the tube and circulates it. Is that correct? Does it move enough water to justify putting that big piece of pvc in the tank ? Obviously tube size and pump size are factors, do you need a huge airpump to make it work? What about salt spray?
BTW, I've built some surge devices, and the concept of putting it right in the tank sounds uhhhh unique. Of course mine were built out of garbage cans with toilet flappers :eek1: .
Agu
piercho
New member
"bubbles force water up the tube and circulates it. Is that correct? " For practical purposes, yes. I think the actual physics is that the water column is sucked up the tube.
"Does it move enough water to justify putting that big piece of pvc in the tank ? "
Air lifts can move a lot of water. Here are some reasonable flow rates for un-restricted (in the tank with no plumbing) 2' and 4' lifts:
1" pipe
1.0CFM 1.5CFM 2.0CFM
24" 8GPM 10GPM 13GPM
48" 21GPM 24GPM 28GPM
1.5" pipe
1.0CFM 1.5CFM 2.0CFM
24" 16GPM 17GPM 18GPM
48" 36GPM 36GPM 42GPM
2" Pipe
1.0CFM 1.5CFM 2.0CFM
24" 20GPM 24GPM 30GPM
48" 42GPM 48GPM 61GPM
(source: old ACS catalog)
Now, if you plumb the lift external, like I did, plumbing resistance knocks the flow down a lot. For instance, my lift is 4' tall and has a 1.5" diameter and I inject about 1.5 CFM of air. My flow is 20 GPM, plumbed external, while the chart value is 36 GPM. I'm fairly certain I could get the chart value if the lift was internal to the tank.
"do you need a huge airpump to make it work? "
I use a Medo AC602 which injects 1.5 CFM of air at 4' of head. As a comparison, most hobby pumps put out less than 0.25 CFM at no head. The actual pump, however, only measures something like 7"X4"X5" and consumes around 45W. There are a few of us snatching these up off eBAy for around $35, each. I have 2. New from a Medo distributor, I think they are over $200.
You could probably build a decent 2'X1" air lift and power it with a TetraTec DW96-2 (or similar) and move a lot of water.
Aquatic Eco-system catalog are excellent for air-lift projects because their pumps are thoroughly rated and they have all the special air doodads you can't get from hobby vendors.
"What about salt spray? " IMO, it would be terrible. My lift is entirely enclosed into a vented collection tank for just this reason.
"Of course mine were built out of garbage cans with toilet flappers "
Well, to imagine an RCSD, think about that garbage can turned upside down and push under the water's surface. So, you've now got a few gallons of air pushed under the water, and the tank's water level is pushed up because of this. Now, imagine that you've installed a 1" valve in the base of the garbage can. You open the valve and all the air vents out in a fraction of second, replaced by water rushing in. The in-rush of water is the surge. To get the water back out, you close the valve and pump air in. That's basically how it works, except that the "valve" is a specially shaped pipe vent and operates with no moving parts.
If you JUST want to move a lot of water efficiently, I'd use one of those ReefTecs pump mods or new Tunze pumps. The Tunze moves something like 3000GPH at 40W, and has infinately adjustable speeds because it is 28VDC instead of AC. The Tunze also can be bought with a cycle controller, speed controller, and a whole bunch of other super-whamadine features. It's pretty amazing (including it's cost).
"Does it move enough water to justify putting that big piece of pvc in the tank ? "
Air lifts can move a lot of water. Here are some reasonable flow rates for un-restricted (in the tank with no plumbing) 2' and 4' lifts:
1" pipe
1.0CFM 1.5CFM 2.0CFM
24" 8GPM 10GPM 13GPM
48" 21GPM 24GPM 28GPM
1.5" pipe
1.0CFM 1.5CFM 2.0CFM
24" 16GPM 17GPM 18GPM
48" 36GPM 36GPM 42GPM
2" Pipe
1.0CFM 1.5CFM 2.0CFM
24" 20GPM 24GPM 30GPM
48" 42GPM 48GPM 61GPM
(source: old ACS catalog)
Now, if you plumb the lift external, like I did, plumbing resistance knocks the flow down a lot. For instance, my lift is 4' tall and has a 1.5" diameter and I inject about 1.5 CFM of air. My flow is 20 GPM, plumbed external, while the chart value is 36 GPM. I'm fairly certain I could get the chart value if the lift was internal to the tank.
"do you need a huge airpump to make it work? "
I use a Medo AC602 which injects 1.5 CFM of air at 4' of head. As a comparison, most hobby pumps put out less than 0.25 CFM at no head. The actual pump, however, only measures something like 7"X4"X5" and consumes around 45W. There are a few of us snatching these up off eBAy for around $35, each. I have 2. New from a Medo distributor, I think they are over $200.
You could probably build a decent 2'X1" air lift and power it with a TetraTec DW96-2 (or similar) and move a lot of water.
Aquatic Eco-system catalog are excellent for air-lift projects because their pumps are thoroughly rated and they have all the special air doodads you can't get from hobby vendors.
"What about salt spray? " IMO, it would be terrible. My lift is entirely enclosed into a vented collection tank for just this reason.
"Of course mine were built out of garbage cans with toilet flappers "
Well, to imagine an RCSD, think about that garbage can turned upside down and push under the water's surface. So, you've now got a few gallons of air pushed under the water, and the tank's water level is pushed up because of this. Now, imagine that you've installed a 1" valve in the base of the garbage can. You open the valve and all the air vents out in a fraction of second, replaced by water rushing in. The in-rush of water is the surge. To get the water back out, you close the valve and pump air in. That's basically how it works, except that the "valve" is a specially shaped pipe vent and operates with no moving parts.
If you JUST want to move a lot of water efficiently, I'd use one of those ReefTecs pump mods or new Tunze pumps. The Tunze moves something like 3000GPH at 40W, and has infinately adjustable speeds because it is 28VDC instead of AC. The Tunze also can be bought with a cycle controller, speed controller, and a whole bunch of other super-whamadine features. It's pretty amazing (including it's cost).
I built the 6-lift on central raceway version for a brine shrimp tank...in my case, I used the one inch diameter clear lift tubes for UGFs, cemented them onto a piece of acrylic and used it for a 10 gal culture tank.
The flow is generated by a combination of the six tubes creating a raceway current in the tank - you get a nice rolling current to keep the brine suspended (I also used flexible acrylic to cut off the tank corners, creating an oval shape)
It works fine for an unimpeded culture tank...I wouldn't consider it enough current to deal with a reef tank and the need to push water through live rock...It's also alot of equipment to water volume in the tank - again, great for a culture tank, but not so well suited for a display tank.
I think it would lend itself to something like a sea-grass lagoon cube with 4 sided viewing...You could stack the rock against the center wall, camouflauge the airlift tubes, and let the current roll around the four open sides...it would keep any food rolling through the water column for particle carnivores like jawfish and garden eels...
But I'm getting enough of a similar effect with just one Reeftec (PE1) in a 90 gal. I don't get the same bottom-to-top roll, but the racetrack current is strong enough to do the job. And I don't think the single plastic prop hurts the plankton - there's too much associated water movement to hold the organisms away from the blade.
India
The flow is generated by a combination of the six tubes creating a raceway current in the tank - you get a nice rolling current to keep the brine suspended (I also used flexible acrylic to cut off the tank corners, creating an oval shape)
It works fine for an unimpeded culture tank...I wouldn't consider it enough current to deal with a reef tank and the need to push water through live rock...It's also alot of equipment to water volume in the tank - again, great for a culture tank, but not so well suited for a display tank.
I think it would lend itself to something like a sea-grass lagoon cube with 4 sided viewing...You could stack the rock against the center wall, camouflauge the airlift tubes, and let the current roll around the four open sides...it would keep any food rolling through the water column for particle carnivores like jawfish and garden eels...
But I'm getting enough of a similar effect with just one Reeftec (PE1) in a 90 gal. I don't get the same bottom-to-top roll, but the racetrack current is strong enough to do the job. And I don't think the single plastic prop hurts the plankton - there's too much associated water movement to hold the organisms away from the blade.
India
piercho
New member
Fred: I'm pretty sure India's lift is in-tank. The system i have is adjacent to the tank, with the water in the collection tank at the same level as the reef tank. Eco-wheel, an air-driven ATS which is the only air-driven hobby system that I'm aware of, also sits adjacent to the tank. air-lifts can create very little head, so they aren't useful to pump water from a lower resevoir up unless the height difference is very small (a couple of inches).
a air-driven surge (RCSD) has to have it's functional volume below the tank water level. Mine sits adjacent, others put theirs in the tank. It would be possible to plumb a RCSD under the tank, but I've never seen or heard of anyone doing it.
a air-driven surge (RCSD) has to have it's functional volume below the tank water level. Mine sits adjacent, others put theirs in the tank. It would be possible to plumb a RCSD under the tank, but I've never seen or heard of anyone doing it.
picture the reef
New member
airlift circulation/surge
airlift circulation/surge
If you really want to see an effective version of this idea go to aquatic engineers web site about the ECO WHEEL filtration system. Granted the initial cost of this system seems great but if you figure the advantages in long term cost savings it is not that expensive. I have ordered one of their systems and will post an opinion as soon as I've formed one. Hope this helps.
airlift circulation/surge
If you really want to see an effective version of this idea go to aquatic engineers web site about the ECO WHEEL filtration system. Granted the initial cost of this system seems great but if you figure the advantages in long term cost savings it is not that expensive. I have ordered one of their systems and will post an opinion as soon as I've formed one. Hope this helps.
Piercho, thanks for all the info, I'm begging for more pics 
. I'm thinking about undertaking the same year long quest for a system I'm developing in my head that's similar to yours.
Agu, here's the link for the RSCD. Here is another link for an RSCD out of 6" pvc pipe. This is the link to Piercho's thread with more details about his lifts incl some pictures.
Piercho, could you give us more details about how you've vented/purged the air at the top of the lift? How long is the horizontal run back to the tank? Where along this run is your vent? What size vent did you use? Many thanks!
- Tom
. I'm thinking about undertaking the same year long quest for a system I'm developing in my head that's similar to yours.Agu, here's the link for the RSCD. Here is another link for an RSCD out of 6" pvc pipe. This is the link to Piercho's thread with more details about his lifts incl some pictures.
Piercho, could you give us more details about how you've vented/purged the air at the top of the lift? How long is the horizontal run back to the tank? Where along this run is your vent? What size vent did you use? Many thanks!
- Tom
piercho
New member
Tom: PM me and I'll send you a pretty good diagram with side, front, and overhead views monday. I tried posting a .gif version but the layout is too large for RC. On the pics, i gotta finish the roll of film, first.
"more details about how you've vented/purged the air at the top of the lift?" The air-lift collection tank air-space serves as the place to handle the air-lift and RCSD spray and noise, away from the main tank. All the lift and RCSD air vents from the collection tank using 3/4" poly pipe. The collection tank (where the airlift output is "de-bubbled") is entirely sealed with the exception of the vent. When the RCSD cycles (vents), it blows into the collection tank air space and out the collection tank vent. The collection tank and RCSD are made of 6" PVC. The function of my RCSD vent is identical to the diagram in Kevin Carpenter's article. I use 2 fittings into the collection tank: one barely below the waterline to refill the vent pipe after vent, one a couple of inches abouve the water line. My vent piping is 3/4" PVC, water piping to the RCSD is 2" ABS.
I looked at Chris's diagram and the function of his external RCSD is similar to mine. My concern is, with a tall RCSD, when it vents the water ejected from the vent pipe will spray and make a lot of noise. So, personally, I wouldn't have choose to vent directly to the main tank. I'd vent it into some kind of enclosure to contain the spray and limit the noise. And I'd use a vent fitting just below the water line and one a couple of inches above, like is shown in the Carpenter article.
"How long is the horizontal run back to the tank? "
My total length of inlet and outlet piping is about 14' of 2" ABS, with 5 long sweep elbows and 2 medium sweep. This tank is not drilled so I went over the top with the inlet and outlet, which adds elbows and pipe length.
"Where along this run is your vent? " N/A. The diagram should make this apparent, I hope.
"more details about how you've vented/purged the air at the top of the lift?" The air-lift collection tank air-space serves as the place to handle the air-lift and RCSD spray and noise, away from the main tank. All the lift and RCSD air vents from the collection tank using 3/4" poly pipe. The collection tank (where the airlift output is "de-bubbled") is entirely sealed with the exception of the vent. When the RCSD cycles (vents), it blows into the collection tank air space and out the collection tank vent. The collection tank and RCSD are made of 6" PVC. The function of my RCSD vent is identical to the diagram in Kevin Carpenter's article. I use 2 fittings into the collection tank: one barely below the waterline to refill the vent pipe after vent, one a couple of inches abouve the water line. My vent piping is 3/4" PVC, water piping to the RCSD is 2" ABS.
I looked at Chris's diagram and the function of his external RCSD is similar to mine. My concern is, with a tall RCSD, when it vents the water ejected from the vent pipe will spray and make a lot of noise. So, personally, I wouldn't have choose to vent directly to the main tank. I'd vent it into some kind of enclosure to contain the spray and limit the noise. And I'd use a vent fitting just below the water line and one a couple of inches above, like is shown in the Carpenter article.
"How long is the horizontal run back to the tank? "
My total length of inlet and outlet piping is about 14' of 2" ABS, with 5 long sweep elbows and 2 medium sweep. This tank is not drilled so I went over the top with the inlet and outlet, which adds elbows and pipe length.
"Where along this run is your vent? " N/A. The diagram should make this apparent, I hope.
Real lift? or just water movement
Real lift? or just water movement
I guess I must be missing something. Does the airlift actually raise the water, as in could I use this to go from a sump to a tank? How much head can you get out of this system?
I hate sounding stupid, but I hate even worse staying stupid.
Real lift? or just water movement
I guess I must be missing something. Does the airlift actually raise the water, as in could I use this to go from a sump to a tank? How much head can you get out of this system?
I hate sounding stupid, but I hate even worse staying stupid.
The air moves the water along with it as it rises up the tube. It can move many gpm, but drops off severely in performance if forced to push water more than a couple inches higher than static. This is why it is best used for in tank circulation.
HTH,
Chris
HTH,
Chris
johnrags1234
New member
Cool project everyone! I might try doing something like this, and the great thing is is that I HAVE the parts for this one!
LiquidShaneo
Reefer
I've got two .mpg's of my 20 gal prop tank that was run by airlifts. Hit http://www.liquidreef.com/ and click on the Prop Tub link on the menu at the left. They worked great for me at the time with minimal salt creep. Since then I've setup a small 10 gal prop tank in my basement using only airlifts and it's working just fine.
Shane
Shane
Re: Re: Real lift? or just water movement
Re: Re: Real lift? or just water movement
Ok, that makes more sense.
So, effectively, it could get a modeate/low volume of water to or from a refugium within, say, 10 inches or so of the same level as the display tank without harming the critters, then whichever was higher would overflow to the lower tank, again without damaging critters. Any other flow would also be provided by in-tank airlifts, and the only sound from the system would be the air pumps, which could easily be anywhere (like in a garage, to eliminate the noise) and the bubbles rising.
Anything else I'm missing?
Re: Re: Real lift? or just water movement
TJG said:
Ok, that makes more sense.
So, effectively, it could get a modeate/low volume of water to or from a refugium within, say, 10 inches or so of the same level as the display tank without harming the critters, then whichever was higher would overflow to the lower tank, again without damaging critters. Any other flow would also be provided by in-tank airlifts, and the only sound from the system would be the air pumps, which could easily be anywhere (like in a garage, to eliminate the noise) and the bubbles rising.
Anything else I'm missing?
chrislove01
New member
Skimmer??
Skimmer??
So all these airlifts to save the critters, I like the idea, might do that on my system.
But what about when you have a skimmer ripping all the critters out.....
Surely defeats the object.... I will be skimmer less I think so these airlifts sound excellent.
Thoughts?
Chris
Skimmer??
So all these airlifts to save the critters, I like the idea, might do that on my system.
But what about when you have a skimmer ripping all the critters out.....
Surely defeats the object.... I will be skimmer less I think so these airlifts sound excellent.
Thoughts?
Chris
LiquidShaneo
Reefer
The whole point with airlifts is that you can move a LOT of water with minimal energy input -- a lot less energy input than running a high GPH mag-drive pump. Saving the critters is a side benefit. Tropicorium up in Romulus, MI, runs their 20'x5'x4' deep tanks on a single high CFM blower. We're talking about running 10-12 of those large tanks on *one* high CFM blower and they have a LOT of flow in all of their tanks.
Shane
Shane
piercho
New member
Thallone: I think you are going to want to have the refugium adjacent to, not below the main tank. If you still want to try to lift the water from a lower tank, post or PM me your % submergence (submerged pipe length/total pipe length * 100), length of pipe, pipe diameter, and desired flow rate. From this I can estimate your needed air injection. If you don't have at least 40% submergence the idea is not feasable to start with.
IMO, for sump sytems and below-tank refugias, just pump the water up with a centrifugal pump. Adey never said (Dr W. Adey, "Dynamic Aquaria") that centrifugal pumps will kill all plankters. What he said was that centrifugal pumps may influence the diversity of plankters, and his preference was to use non-traumatic pumps. He used some sort of diaphragm-type pump.
IMO, to use an air lift to move water between a refugia tank and a main tank, the refugia water level should be equal to, or slightly above, the main tank.
IMO, for sump sytems and below-tank refugias, just pump the water up with a centrifugal pump. Adey never said (Dr W. Adey, "Dynamic Aquaria") that centrifugal pumps will kill all plankters. What he said was that centrifugal pumps may influence the diversity of plankters, and his preference was to use non-traumatic pumps. He used some sort of diaphragm-type pump.
IMO, to use an air lift to move water between a refugia tank and a main tank, the refugia water level should be equal to, or slightly above, the main tank.
