2 MagDrive 9.5s ok in a 10g Sump?
- Thread starter ReefDreamin'
- Start date
Radical Departure Alert
The rest of the group has been offering advice to help you run 20x tank volume through your sump. I'd like to offer some very different advice: use a closed loop for half or all of your wavemaking circuit. You'll be able to cut the pump size in half (because there won't be any head to work against), and you'll have space in the sump to make a decent sump.
Pushing 50x sump volume through a lossy circuit is wasteful of energy and an invitation to heat problems. I think that the reason to drop water into a sump and take the hit of pumping it back up to the tank is to let filters and refugiums do good things for the water out of sight. If all you're doing is picking up the water and throwing it back in the main tank, close the loop and save yourself the energy loss.
I wrote a diatribe against overusing the sump circuit a while back on reefs.org. You may find it interesting reading. An even more efficient method of wavemaking (mentioned in the article) are the Tunze Turbelle Stream pumps. While fairly expensive, they pump huge amounts of water for very little energy (the 6100 consumes 15W to produce 1800gph of moderate-velocity, speed-controlled flow).
Regards,
Ross
The rest of the group has been offering advice to help you run 20x tank volume through your sump. I'd like to offer some very different advice: use a closed loop for half or all of your wavemaking circuit. You'll be able to cut the pump size in half (because there won't be any head to work against), and you'll have space in the sump to make a decent sump.
Pushing 50x sump volume through a lossy circuit is wasteful of energy and an invitation to heat problems. I think that the reason to drop water into a sump and take the hit of pumping it back up to the tank is to let filters and refugiums do good things for the water out of sight. If all you're doing is picking up the water and throwing it back in the main tank, close the loop and save yourself the energy loss.
I wrote a diatribe against overusing the sump circuit a while back on reefs.org. You may find it interesting reading. An even more efficient method of wavemaking (mentioned in the article) are the Tunze Turbelle Stream pumps. While fairly expensive, they pump huge amounts of water for very little energy (the 6100 consumes 15W to produce 1800gph of moderate-velocity, speed-controlled flow).
Regards,
Ross
I just wanted to reiterate in this thread of the importance, IMHO, of having two smaller return pumps rather than one large one. I do the same thing with heaters. One will eventually fail; this is a guarantee. It may take several years, but it will happen. If you're at work or away for several hours when it happens, you'll thank that backup.
That's actually okay. You can hang a closed loop on the back of the tank pretty easily. Once you get enough water in the loop to ensure that the pump will never run completely dry, a properly pumped loop will self-purge the remaining air in less than a minute.
What I'm hoping is that he'll realize the difficulties he's getting into by trying to pump that much through a sump circuit and start considering alternative approaches to adding circulation to his tank.
He may not like the looks of pumps in the main tank, but his situation is one where they make a lot of sense. I know they're expensive, but the Tunze pumps are really made for this type of situation. Powerheads with homemade eductors would be less polished but would result in similar performance for a lot less $$$. Finally, some sort of a closed loop (or two) would put pipes instead of pumps in the tank but is more complex than other approaches.
Seconded. I'm very much in favor of having two of everything. Redundancy is also another argument for having in-tank pumps for some circulation (redundant kinds of circulation, not only redundancy of the same kind). If an in-tank pump stalls for a day while you're at work, a few animals would be less happy about the reduced current, but they're not completely out of luck.
Also, as long as you didn't let a Rio near your tank, a pump failure is unlikely to belch toxic goop into your tank water, taking the whole tank with it. He's already mentioned using Mags, so it appears he may have already heard to avoid Rio, but it's worth mentioning in any discussion of aquarium pumps (IMNSHO).
Regards,
Ross
"That's actually okay. You can hang a closed loop on the back of the tank pretty easily. Once you get enough water in the loop to ensure that the pump will never run completely dry, a properly pumped loop will self-purge the remaining air in less than a minute."
I was always under the impression the pump would need to be primed again any time the power went off, or else it would burn out. Can you post a pic or diagram of how to do this?
I was always under the impression the pump would need to be primed again any time the power went off, or else it would burn out. Can you post a pic or diagram of how to do this?
Hm. My drawing tools suck (the darned thing is crashing 
) and I'm having trouble coming up with a drawing. Let's see if I can talk you through it.
Think of the hang-on-loop as being a single line of tubing starting in the tank, going over the edge, down to the pump, back up over the edge and back down into the tank. At this point, divide that length into three segments. Segment one is the part leading from the intake nozzle to the edge of the tank. Segment two goes from the edge of the tank, down to the pump, and back up to the edge of the tank. Segment three goes from the edge of the tank through to the spray nozzle in the tank. There are no siphon breaks in a closed loop and both ends should be under water when on the tank.
When you first set up the pump, you can only easily prime segment two. Segments one and three tend to drain when the loop is being rehung on the tank. When the loop is first put on the tank, all of the openings are submerged and segments one and three are filled with air. The pump starts and segment three quickly burps it's air into the tank while the air that was in segment one heads for the pump. As long as segment one is sufficiently small compared to the distance between the edge of the tank and the pump, that bubble will get pulled through and pumped out the other side.
The important bit is the size of the bubble in segment one. If there's enough air trapped in segment one that you can't get a clean siphon started on the intake side before the bubble gets to the pump, the loop won't start by itself. If the pump is located below the tank, however, this is very unlikely. Also, I've seen irrigation syringes with short hoses used to prime the closed loop while it was hanging on the tank (which allows you to prime the whole circuit). Push the hose up into segment one and pull the air from the top of that siphon. You won't get all of it, but the miniscule bubble that remains won't cause you any problems.
Your question went to the power-off failure mode. Well, since there are no siphon breaks needed or desired in a closed circuit, the loop should remain fully primed, and all three segments will remain full of water. Some of the products that you might put on the output may helpfully include a siphon break, which just means that segment three would drain while the power was off. When the power turned back on, that bubble would get pushed back into the tank and off you go again. If you do decide to put a siphon break on segment one, that too will drain into the tank, but only to the level of the tank. This is at most an inch and a half below the edge of the tank which should be very easy to restart.
Now, this design assumes that the closed loop pump is placed below the tank, or at least below the surface of the water in the tank (perhaps the pump is resting on the same stand as the tank). This approach means that the static pressure is working in your favor and helps the system self-prime. I have seen one case where someone tried to put the whole pump and closed loop in the hood above the tank, but he was never able to get it to work well. As you said, during a power loss, the thing drained itself back into the tank and was unable to restart on restoration of power.
I hope that was clear enough. If not, I'll work on a drawing and see if I can't come up with something.
Regards,
Ross
) and I'm having trouble coming up with a drawing. Let's see if I can talk you through it.Think of the hang-on-loop as being a single line of tubing starting in the tank, going over the edge, down to the pump, back up over the edge and back down into the tank. At this point, divide that length into three segments. Segment one is the part leading from the intake nozzle to the edge of the tank. Segment two goes from the edge of the tank, down to the pump, and back up to the edge of the tank. Segment three goes from the edge of the tank through to the spray nozzle in the tank. There are no siphon breaks in a closed loop and both ends should be under water when on the tank.
When you first set up the pump, you can only easily prime segment two. Segments one and three tend to drain when the loop is being rehung on the tank. When the loop is first put on the tank, all of the openings are submerged and segments one and three are filled with air. The pump starts and segment three quickly burps it's air into the tank while the air that was in segment one heads for the pump. As long as segment one is sufficiently small compared to the distance between the edge of the tank and the pump, that bubble will get pulled through and pumped out the other side.
The important bit is the size of the bubble in segment one. If there's enough air trapped in segment one that you can't get a clean siphon started on the intake side before the bubble gets to the pump, the loop won't start by itself. If the pump is located below the tank, however, this is very unlikely. Also, I've seen irrigation syringes with short hoses used to prime the closed loop while it was hanging on the tank (which allows you to prime the whole circuit). Push the hose up into segment one and pull the air from the top of that siphon. You won't get all of it, but the miniscule bubble that remains won't cause you any problems.
Your question went to the power-off failure mode. Well, since there are no siphon breaks needed or desired in a closed circuit, the loop should remain fully primed, and all three segments will remain full of water. Some of the products that you might put on the output may helpfully include a siphon break, which just means that segment three would drain while the power was off. When the power turned back on, that bubble would get pushed back into the tank and off you go again. If you do decide to put a siphon break on segment one, that too will drain into the tank, but only to the level of the tank. This is at most an inch and a half below the edge of the tank which should be very easy to restart.
Now, this design assumes that the closed loop pump is placed below the tank, or at least below the surface of the water in the tank (perhaps the pump is resting on the same stand as the tank). This approach means that the static pressure is working in your favor and helps the system self-prime. I have seen one case where someone tried to put the whole pump and closed loop in the hood above the tank, but he was never able to get it to work well. As you said, during a power loss, the thing drained itself back into the tank and was unable to restart on restoration of power.
I hope that was clear enough. If not, I'll work on a drawing and see if I can't come up with something.
Regards,
Ross
Actually, rabagley's idea works. As I mentioned in this or the sister thread, I used an external MagDrive on the sump with the help of a U-tube (siphon) As long as the water line does not go below the ends of the U-tube, and the pump is below the waterline even during power outage, the siphon will be fine to go when the power come back.
The advantage of a close loop (more flow for less energy/heat) should makes you considering it. Good call, rabagley.
The advantage of a close loop (more flow for less energy/heat) should makes you considering it. Good call, rabagley.
I feel I have to chime in here
I have a 55 gallon tank with a 20 gallon sump
I am using an Iwaki md30xrlt for a return pump
I have 2 1" drains and a 1 inch return
This is way too much flow going through the sump. I am very unhappy with this arrangement, and if I was going to do it over I would go with a closed loop and a small pump for the return from the sump.
Hope that helps
I have a 55 gallon tank with a 20 gallon sump
I am using an Iwaki md30xrlt for a return pump
I have 2 1" drains and a 1 inch return
This is way too much flow going through the sump. I am very unhappy with this arrangement, and if I was going to do it over I would go with a closed loop and a small pump for the return from the sump.
Hope that helps
Wow....maybe I'm a little slow here but my head is still spinning from your post Ross! I'm trying to get a picture in my mind to understand your suggested set up...unfortunately I learn better with pictures than with words alone, so if you could possibly post a drawing, that would be really great. Do you mean I should use one pump to make a closed loop system in the main tank, and use a separate pump in the sump? This would provide more circulation in the tank without having to run all the circulation through the sump...do I have that right? I do like the idea of having two pumps, like Matt suggested, just in case something goes wrong. And yes, I have heard about those notorious Rios so I'll be sure to stay away from them.
It's not that I don't have the option of drilling my tank or sump, I just don't know of anywhere around me (I live in Jersey farm country - we are after all, called "The Garden State" :wink: ) that would be able to drill through glass. I really like Matt's idea about removing one of the side panes and replacing it with drilled acrylic though. That could be an option.
It's not that I don't have the option of drilling my tank or sump, I just don't know of anywhere around me (I live in Jersey farm country - we are after all, called "The Garden State" :wink: ) that would be able to drill through glass. I really like Matt's idea about removing one of the side panes and replacing it with drilled acrylic though. That could be an option.
This might help. I think this is exactly what you're looking for...
http://www.sparklingfloorservice.com/ta ... dloop.html
http://www.sparklingfloorservice.com/ta ... dloop.html
That's exactly the type of closed loop I'm talking about. It's more complex than the simple case I was explaining, but it includes the wavemaker so it's even better as an example of what ReefDreamin may want to do. ReefDreamin may want to locate the closed loop pump in the stand under the tank, which will make the whole thing look somewhat different, but that is pretty much it.HClH2OFish":tkpo48iu said:
Correct on both questions.ReefDreamin":tkpo48iu said:
Since you've got the space for a sump under your tank, I'd add the sump with a pump that gives you decent circulation for a tank to sump circuit.
If that's not enough circulation (and you appear to want more than the 200gph circulation that I would say is aggressive for a 10gal sump), then add more, using either a "hang-on" closed loop like the one in the above URL, a powerhead in the tank, a circulation pump in the tank (Jimmy Chen's propellor pump, Tunze Stream, powerhead + eductor, etc.).
The approach closest to your original plan is to attach one wavemaker (and two return nozzles) to the sump return and change the other wavemaker (with the other two return nozzles) to be a closed circuit. The pumps will not be the same size since the closed circuit won't have the head pressure that the sump return has to work against.
Regards,
Ross
ReefDreamin'":3aymrms6 said:Wow....maybe I'm a little slow here but my head is still spinning from your post Ross! I'm trying to get a picture in my mind to understand your suggested set up...unfortunately I learn better with pictures than with words alone, so if you could possibly post a drawing, that would be really great. Do you mean I should use one pump to make a closed loop system in the main tank, and use a separate pump in the sump? This would provide more circulation in the tank without having to run all the circulation through the sump...do I have that right? I do like the idea of having two pumps, like Matt suggested, just in case something goes wrong. And yes, I have heard about those notorious Rios so I'll be sure to stay away from them.
It's not that I don't have the option of drilling my tank or sump, I just don't know of anywhere around me (I live in Jersey farm country - we are after all, called "The Garden State" :wink: ) that would be able to drill through glass. I really like Matt's idea about removing one of the side panes and replacing it with drilled acrylic though. That could be an option.
Okay, you are freaking me out
I did not know there were any more fish tanks here in South Jersey
I got my tank drilled at a fish store in Pleasantville I think, if you are interested I will look up the name of it.
I am by millville and Vineland, anywhere close to you?
Thanks everyone for your help...that web link with the closed loop system & SCWD is great....it's just what I'm looking for.
Knucklehead, I'm actually not as far south as you are. I'm closer to Willingboro...that's about an hour away from Pleasantville I think. I know what you mean about the lack of South Jersey fish tanks...I can see nothing but corn fields and cows/horses around here. Which LFS do you go to? The Aquarium Center in Clemonton is about 35 minutes south of me, but there aren't any others I know of.
Knucklehead, I'm actually not as far south as you are. I'm closer to Willingboro...that's about an hour away from Pleasantville I think. I know what you mean about the lack of South Jersey fish tanks...I can see nothing but corn fields and cows/horses around here. Which LFS do you go to? The Aquarium Center in Clemonton is about 35 minutes south of me, but there aren't any others I know of.
That is the only one I go to. Its about an hour drive north for me.
I don't usually go to the one in Pleasantville, but I did to get the tank drilled as it was the only place I could find. They did have a ton of fish, but they will sell anything to anybody, and that kind of rubs me the wrong way. sending someone out of a store with a 10 gallon tank and a lionfish is just not right
Sponsor Reefs
We're a FREE website, and we exist because of hobbyists like YOU who help us run this community.
Click here to sponsor $10:
